7Van den Besselarr,P,Heimeriks,G. Mapping research topics using word- reference co- occurrences: A method and an exploratory case study[ J]. Scientometrics,2006,68(3) :377 - 393.
8Morris, S A,Van der Veer Martens B. Modeling and Mapping of Research Specialties[ J]. The Annual Review of Information Science and Technology,2007,42(3) : 13.
9Garfield,E. Citation index for science: A new dimension in documontation through association of ideas[J]. Science, 1955, 122 (3159) :108- 111.
10Kessler, M M. Bibliographic coupling between scientific papers [ J]. American Documentation, 1963, (14) : 10- 25.
