human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "a spatial scientometric analysis of the publication output of cities worldwide"):
  Abstract: In tandem with the rapid globalisation of science, spatial scientometrics has become an important research sub-field in scientometric studies. Recently, numerous spatial scientometric contributions have focused on the examination of cities' scientific output by using various scientometric indicators. In this paper, I analyse cities' scientific output worldwide in terms of the number of journal articles indexed by the Scopus database, in the period from 1986 to 2015. Furthermore, I examine which countries are the most important collaborators of cities. Finally, I identify the most productive disciplines in each city. I use GPS Visualizer to illustrate the scientometric data of nearly 2,200 cities on maps. Results show that cities with the highest scientific output are mostly located in developed countries and China. Between 1986 and 2015, the greatest number of scientific articles were created in Beijing. The international hegemony of the United States in science has been described by many studies, and is also reinforced by the fact that the United States is the most important collaborator to more than 75 percent of all cities. Medicine is the most productive discipline in two-thirds of cities. Furthermore, cities having the highest scientific output in specific disciplines show well-defined geographical patterns.

Includes members:
  Member "mapping spatial and temporal changes of global corporate research and development activities by conducting a bibliometric analysis":
    also connected through other hyperedges:
      (none)
  Member "exploring the position of cities in global corporate research and development a bibliometric analysis by two different geographical approaches":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "on the challenges ahead of spatial scientometrics focusing on the city level")
  Member "the journal coverage of web of science and scopus a comparative analysis":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "a tale of two databases the use of web of science and scopus in academic papers")
  Member "how have the eastern european countries of the former warsaw pact developed since 1990 a bibliometric study":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "the evolution of sentiment analysis a review of research topics venues and top cited papers")
  Member "mapping excellence in the geography of science an approach based on scopus data":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "on the challenges ahead of spatial scientometrics focusing on the city level")
  Member "globalisation of science in kilometres":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "making sense of global collaboration dynamics developing a methodological framework to study dis similarities between country disciplinary profiles and choice of collaboration partners")
  Member "the detection of hot regions in the geography of science a visualization approach by using density maps":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "on the challenges ahead of spatial scientometrics focusing on the city level")
  Member "mapping the geography of science distribution patterns and networks of relations among cities and institutes":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "on the challenges ahead of spatial scientometrics focusing on the city level")

Question: Please tell me which class the source paper 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)