1. Lin, X., Ahn, J.W.: Challenges of knowledge structure visualization. In: Classification and visualization: interfaces to knowledge: Proceedings of the International UDC Seminar, October 24-25, 2013, The Hague, The Netherlands. Ergon Verlag, 2013 (2013)
2. Johnson, B., Shneiderman, B.: Tree-maps: a space-filling approach to the visual-ization of hierarchical information structures. In: VIS ’91: Proceedings of the 2nd conference on visualization ’91. pp. 284–291. IEEE Computer Society Press, Los Alamitos, CA, USA.
http://portal.acm.org/citation.cfm?id=949654
(1991)
3. Sintek, M.: Ontoviz,
http://protegewiki.stanford.edu/wiki/OntoViz
. Accessed Nov 2016
4. Grefenstette, G.: Explorations in automatic thesaurus discovery. Springer, New York (1994)
5. Koopman, R., Wang, S., Scharnhorst, A.: Contextualization of topics—browsing through terms, authors, journals and cluster allocations. In: Proceedings of 15th international conference on scientometrics and informetrics. Istanbul, Turkey (2015)