1. Brachman R.J. , Levesque H.J. and Reiter R. , Knowledge representation, MIT Press, 1992.
2. Recursive database structures;Brandon;J Comput Sci Coll,2005
3. Universal networking language: Advances in theory and applications;Cardeñosa;Research on Computer Science,2005
4. Retrieval time from semantic memory;Collins;Journal of Verbal Learning and Verbal Behavior,1969