1. BARBUT, M. and MONJARDET, B. (1970): Ordre et classification, Algebre et combinatoire. Hachette, Paris.
2. BARTHÉLEMY, J.P., LECLERC, B. and MONJARDET, B. (1986): On the use of ordered sets in problems of comparison and consensus of classifications. Journal of Classification, Vol. 3, 187–224.
3. BIRKHOFF, G. (1967): Lattice Theory (3rd ed.). Amer. Math. Soc, Providence, R.I.
4. BLYTH, T.S. and JANOWITZ, M.F. (1972): Residuation Theory. Pergamon Press, Oxford.
5. BOCK, H.H. and DIDAY, E. (2000): Analysis of symbolic data. Studies in Classification, Data analysis and Knowledge organization, Springer, Berlin.