human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "the practice of self citations a longitudinal study"
  Abstract: In this work, we discuss the result of an experiment that wants to track how authors use self-citations in their articles. In particular, we have analysed a subset of all the articles published between 1959 and 2016 in ScienceDirect written by the participants to the 2012-2013 Italian Scientific Habilitation so as to see if their citation habits have changed after 2012 as a consequence of the evaluation guidelines published by ANVUR (the Italian National Agency for the Evaluation of the University and Research Systems) in 2012 that have been used for assessing the quality of scholars' research. The results showed a clear increasing trend in author self-citations (i.e. those ones in which the citing and the cited bibliographic resources have at least one author in common) in several of the academic disciplines considered. Instead, no clear trend has been observed overall for author network self-citations (i.e. those ones in which at least one author of the citing bibliographic resource has direct or indirect co-authorship links with one of the authors of the cited bibliographic resource), even if a moderate increasing trend has been recorded in a few disciplines.

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.DL(Digital Libraries)