Citation analysis of Veterinary dissertations

The author sought to understand the pattern of use of information resources by the university undergraduates in the Veterinary Medicine and Animal Sciences discipline. This study analyzed 6754 citations from 361 undergraduate dissertations from 2014-2018 submitted to the Faculty of Veterinary Medicine and Animal Sciences, University of Peradeniya, Sri Lanka. According to the findings journals were appeared to be the most preferred source of citation among the Veterinary Medical students. Data sets conformed to the Leimkuhler model derived from Bradford’s law. In the ranked list of core journals in Veterinary science, Journal of dairy science took the first place with 108 citations. Further, results indicated that the students utilized current information mostly for their research. Further observation on authorship patterns of the journal citations indicated that the students of selected veterinary dissertations had mostly cited journal articles which have been authored in collaboration. Recommendations were drawn towards improving the library collection in a user-centric manner and strengthening library instruction. The study contributes to the realm of library literature where 1 Senior Assistant Librarian, Veterinary Medicine & Animal Science Library, University of Peradeniya Email: sureniw1@yahoo.com https://orcid.org/0000-0001-7337-8408 Received: 17 September 2021, Accepted revised version: 22 December 2021 This work is licensed under a Creative Commons Attribution-Share Alike 4.0 International License. Journal of the University Librarians Association of Sri Lanka, Vol. 25, Issue 1, January 2022, 3154, DOI: http://doi.org/10.4038/jula.v25i1.8052 32 research that focuses on citation analysis of Veterinary dissertations which is in scarce.


Introduction
University undergraduates are the main user category to which the university library should cater adequately. The university library collection is the predominant information hub which the undergraduates utilize to meet their information needs. So, it is imperative that the library collection should be developed in a user-centric manner. Librarians should be conscious of changing user demands and design dynamic polices for collection development. Analyzing citations in students' dissertations is a popular and effective way to examine whether the library is in alignment with the user demands (Gunasekera, 2013).
Alan Pritchard first coined the term "Bibliometrics" in 1969 to define "the application of mathematics and statistical methods of books and other media of communication" (Pritchard, 1969, p.349). Citation analysis, a branch of bibliometerics, "measures the utility of documents and relationship between their author and their documents" (Banateppanvar et al., 2013, p.147). This technique helps assess scholarly output, detect significant journals in a discipline, trace research traits and also provides the baseline to form scientific indicators (Zafrunnisha, 2012). It is important that citation studies are conducted consistently and periodically in order to identify numerous developments and changes incorporated into scholarly output with time.
Librarians must recognize their users' information needs. Citation analysis is a powerful tool that helps librarians to make innovative and user-centric collection development decisions to design and enhance user services. Analyzing publications or dissertations submitted to a certain institute is a common approach of citation analysis. Nabe and Imre (2008, para 4) highlight that "dissertations clearly indicate the needs of graduate students, and also indicate the research specialties of the faculty and departments as a whole".
In the development of library collections, documents which are mostly cited are the most significant ones to be included into the library collection (Sudhier, 2010). Also, since journals are of vital importance for research purposes, identifying most and least referred journals is salient in making subscription and cancellation decisions. The highly cited journals, which are "core journals", a notion evolved from the Bradford's law of scattering, "always contain a higher concentration of relevant articles in a particular discipline" (Sudier, 2010, p.3). Citation analysis supports librarians to make effective collection development decisions against financial and space constraints. Moreover, insights into citation patterns would inform decision makers on library instruction and student outreach programs (Wilson, 2012).
The Faculty of Veterinary Medicine and Animal Sciences (FVMAS), University of Peradeniya, Sri Lanka is the only faculty in the discipline of Veterinary Medical Science in Sri Lanka. In the FVMAS it is compulsory for final year undergraduates to carry out a research project and submit a report for their graduation. Copies of these dissertations are deposited at their faculty library, which is also the only Sri Lankan university library catering for users in the Veterinary discipline. The overall objective of the current study is to analyze the citations in undergraduate dissertations to ascertain whether the library is adequately satisfying research needs of the Veterinary medical undergraduates. This study is guided by the following specific objectives: • To detect the most preferred types of publications cited by the student sample  Trigar et al. (2013) analyzed the theses of Dental and Medical science graduates and found that journals were the most popular among the citations. Similar results were obtained by Becker and Chiware (2015) in their examination on of Master and doctoral dissertations in the Engineering discipline. Findings revealed that journals were the most utilized resource by the students. The authors concluded that citation analysis together with other methods is one of the most powerful tools to evaluate whether the library collection is adequately satisfying students' research demands.
In line with the above studies, Fasae (2012), Banateppanvar et al. (2013), Sinha and Singha (2016), Griffin (2016) and Salami and Olatokun (2018) have analyzed citations appended to Masters/PhD theses in diverse disciplines and identified that journals were the most dominant type of citation format among scholars.
However, different results were reported by Mahajan and Kumar (2017). The authors examined citations from PhD dissertations in the History discipline and identified that books were the most frequently used resource by History researchers. In the same way, Rozenburg (2015) also observed that books were the most preferred document of reference in his study of graduate theses in Sociology and Anthropology. Wilson (2012) examined 2301 citations appended to 88 undergraduate honors theses submitted to the University of South Alabama, Library. It was revealed that books and journals were more popular among students in all disciplines except Social Sciences, in which news-papers were heavily cited by the students. In a related study, Gadd et al. (2010)

analyzed final-year projects of MEng Civil
Engineering students and BSc Construction Engineering Management (CEM) students. Overall, the students had cited books (27.5%) more frequently, followed by journals (24.8%). Furthermore, journals were highly cited by the MEng students in comparison with CEM students. Kohn and Gordon (2014) perused bibliographies of undergraduate theses from three departments: Sociology, Psychology and International studies.
The authors found that journals were the most popular source of citation and that more than 70% of these cited journals were accessible through the Library. Thus, it was shown that the undergraduates were more likely to cite what was available in their institution.

Oliveira (1984) conducted a study in the domain of Veterinary
Medicine and Animal Science, in Brazil to trace out the citation trend in Veterinary medicine discipline using Masters Dissertations. Periodicals, which accounted for 70% of total citations, was found to be the most preferred information source consulted by the researchers. The Journal of American Veterinary Medicine Association topped the ranked list of journals. However, the data sets of the study did not satisfy the Bradford's law. Corroborating the above results, Olatokun and Makinde (2009) also found that students mostly cited journals in their study of Masters dissertations submitted to the Department of Animal Science in a Nigerian University. Further, the findings had implications for "both collection development and user service design in libraries" (Olatokun & Makinde, 2009, p.117). (2003) analyzed bibliographic citations appended to twelve core Veterinary journals and observed that 6.38% of citations were grey literature. Also, they found that conferences played a crucial role accounting for 50.1% of the grey literature. It was concluded that the prevalence of grey literature was lower in Veterinary scholarly communications. In another study, Crawley-Low (2006)

Applying the Bradford's law
The Bradford's law is a powerful bibliometric tool that is extensively applied in determining the productivity of journals (Sudhier, 2010). This law outlines the quantitative relationship among journals and the articles contained in them. Journals are compiled in descending order of productivity of articles based on citations of a given subject and divided into three approximately equal zones. Bradford defined the first zone as the "nuclear zone", the second zone as moderately productive and the third zone as the low productive zone (Bardford, 1950;Weerasinghe, 2017). The "nuclear zone" which accounts for a small number of core journals, is highly productive (Weerasinghe, 2017).
Bradford had expressed his law as: [. . .] if scientific journals are arranged in the order of decreasing productivity of articles on a given subject, they may be divided into a nucleus of periodicals more particularly devoted to the subject and several groups or zones containing the same number of articles as the nucleus, where the numbers of periodicals in the nucleus and succeeding zones will be as 1: n: n 2 [. . .] (Bradford, 1950, p. 116). Here 'n' is a multiplier.

Several researchers formulated mathematical models based on
Bradford's Law to better explain the phenomenon of scattering. Leimkuhler (1980)  a and b are constants appearing in the Leimkuhler's law (Weerasinghe, 2017). This can be applied to compute the number of articles in a journal at a certain rank.
While describing Leimkuhler's law, Egghe (1986Egghe ( , 1990aEgghe ( , 1990b verified: a = Yo / log kand b = (k -1) / ro Where ro is the number of sources in the first Bradford's group, Yo is the number of items in every Bradford group and k is the Bradford multiplier. Egghe (1986) derived a mathematical formula to compute k, attributing to the fact that when journals are ranked according to their decreasing order of productivity, Ym will be the number of articles in the rank one journal.
p is the number of groups and a parameter which can be selected freely when creating Bradford groups.
After p and Ym are found, k can be computed using: k = (e γ Ym) 1/p Here γ is Euler's number γ =0.5772 and e γ =1.781 Whereas Yo =Ym 2 log k and ro = (k -1)Ym Egghe (1990aEgghe ( , 1990b has shown that: Yo = A/p, where A is the total number of articles in the bibliography. If T is the total number of journals, in the i th Bradford group, there are rok i-1 journals (i =1, 2, 3, . . .p) (Weerasinghe, 2017).

Applying the Bradford's law
The total number of journal citations (4298) (Table   4). Figure 2 illustrates the Bradford plot for journal distribution which confirms the verbal formulation that detects specific regularity in the organization of scholarly work (Sudhier, 2010). This indicates that only a small numbers of journals are highly cited by students.

Table 4
The distribution of journals and citations according to Leimkuhler model

Figure 2
Bradford plot for journal distribution The results indicate that the nuclear zone consists of 39 highly cited journals (core journals) by the veterinary medical students. Table 5 exhibits the ranked list of core journals. Journal of dairy science, with 108 citations, topped the ranked list while Poultry science secured the

Table 6
Chronological distribution of cited documents

Authorship Patterns of Cited Documents
Analyzing the authorship patterns is a salient attribute of citation analysis. In the current study, the journal citations were selected to determine the authorship pattern. Results revealed that most of the journal citations (62.471%) were by three authors, 19.148% of them were by two authors while 17.799% of citations were by a single author (Table   7).  However, this study has some limitations. This study analyzed all citations in aggregate; hence it does not provide insight into individual use of information resources (Wilson, 2012). Also, the study examined only reference lists of each dissertation which does not ascertain whether all those resources were effectively used within the text. This study focused on final year project reports, therefore the resources utilized are predominantly fulfilling undergraduates' research purposes only.
This study can be further improved by conducting surveys and interviews among library users in order to capture insights into the usage and to enhancing the collection in a user-oriented manner. Also, it is imperative to take into account the commendations of the Faculty to verify whether the current library system is in alignment with the students' requirements.