B. Berstel. TIME '02: Proceedings of the Ninth International Symposium on Temporal
Representation and Reasoning (TIME'02), Seite 49-51. Washington, DC, USA, IEEE Computer Society, (2002)
R. Ungrangsi, C. Anutariya, und V. Wuwongse. Proceedings of the 6th International Semantic Web Conference and 2nd Asian Semantic Web Conference (ISWC/ASWC2007), Busan, South Korea, Volume 4825 von LNCS, Seite 561--574. Berlin, Heidelberg, Springer Verlag, (November 2007)
P. Ciaccia, M. Patella, und P. Zezula. VLDB'97, Proceedings of 23rd International Conference on Very Large Data Bases, August 25-29, 1997, Athens, Greece, Seite 426-435. Morgan Kaufmann, (1997)