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: "an exploratory study of google scholar"
  Abstract: Purpose – The purpose of this paper is to discuss the new scientific search service Google Scholar (GS). It aims to discuss this search engine, which is intended exclusively for searching scholarly documents, and then empirically test its most important functionality. The focus is on an exploratory study which investigates the coverage of scientific serials in GS.Design/methodology/approach – The study is based on queries against different journal lists: international scientific journals from Thomson Scientific (SCI, SSCI, AH), open access journals from the DOAJ list and journals from the German social sciences literature database SOLIS as well as the analysis of result data from GS. All data gathering took place in August 2006.Findings – The study shows deficiencies in the coverage and up‐to‐dateness of the GS index. Furthermore, the study points out which web servers are the most important data providers for this search service and which information sources are highly represented. The paper can show tha...

Connected through hyperedge HE-1 (induced by source paper "are there too many uncited articles zero inflated variants of the discretised lognormal and hooked power law distributions"):
  with members:
    - "the precision of the arithmetic mean geometric mean and percentiles for citation data an experimental simulation modelling approach"
    - "are the discretised lognormal and hooked power law distributions plausible for citation data"
    - "the discretised lognormal and hooked power law distributions for complete citation data best options for modelling and regression"
    - "more precise methods for national research citation impact comparisons"
    - "geometric journal impact factors correcting for individual highly cited articles"
    - "distributions for cited articles from individual subjects and years"
    - "power laws in citation distributions evidence from scopus"
    - "on the calculation of percentile based bibliometric indicators"

Connected through hyperedge HE-2 (induced by source paper "a review of the literature on citation impact indicators"):
  with members:
    - "a sensitivity analysis of researchers productivity rankings to the time of citation observation"
    - "the precision of the arithmetic mean geometric mean and percentiles for citation data an experimental simulation modelling approach"
    - "the journal coverage of web of science and scopus a comparative analysis"
    - "measuring academic influence not all citations are equal"
    - "a review of theory and practice in scientometrics"
    - "comprehensive indicator comparisons intelligible to non experts the case of two snip versions"
    - "methods for estimating the size of google scholar"
    - "large scale analysis of the accuracy of the journal classification systems of web of science and scopus"

Connected through hyperedge HE-3 (induced by source paper "comparing source coverage citation counts and speed of indexing in google scholar and scopus"):
  with members:
    - "methods for estimating the size of google scholar"
    - "empirical patterns in google scholar citation counts"
    - "the google scholar experiment how to index false papers and manipulate bibliometric indicators"

Connected through hyperedge HE-4 (induced by source paper "a new methodology for comparing google scholar and scopus"):
  with members:
    - "methods for estimating the size of google scholar"
    - "empirical patterns in google scholar citation counts"
    - "the google scholar experiment how to index false papers and manipulate bibliometric indicators"

Connected through hyperedge HE-5 (induced by source paper "google scholar as a tool for discovering journal articles in library and information science"):
  with members:
    - "exploring the academic invisible web"

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)