Multivalued monotone mappings are almost everywhere single-valued P. Kenderov — 1976 Studia Mathematica
Bulgarian winter competitions in Mathematics, Informatics and Mathematical Linguistics Svetoslav J. Bilchev; P. Kenderov — 2001 Μαθηματική Επιθεώρηση
A general topology approach to the study of differentiability of convex functions in Banach spaces Kenderov, P. — 1978 Abstracta. 6th Winter School on Abstract Analysis