1. Part–whole relations in object-centered systems: an overview;Artale;Data & Knowledge Engineering,1996
2. The whole–part relationship in object modelling: a definition in cOLOr;Barbier;Information and Software Technology,2001
3. Formalization of the whole–part relationship on the unified modeling language;Barbier;IEEE Transactions on Software Engineering,2003
4. R. Casati, A.C. Varzi, Parts and Places: The Structures of Spatial Representation (A Bradford Book, The MIT Press, Cambridge, Massachusetts, London, England, 1999), Publishing Company 1974 (second ed., Undergraduate Text in Mathematics, Springer Verlag, New York, 1994).
5. http://www.geneontology.org.