Olivier Esser Inconsistency of The Axiom of Choice with The Positive Theory GPK^{+}_{infinite}. [Citation Graph (0, 0)][DBLP] J. Symb. Log., 2000, v:65, n:4, pp:1911-1916 [Journal]

Olivier Esser On the axiom of extensionality in the positive set theory. [Citation Graph (0, 0)][DBLP] Math. Log. Q., 2003, v:49, n:1, pp:97-100 [Journal]

Olivier Esser An Interpretation of the Zermelo-Fraenkel Set Theory and the Kelley-Morse Set Theory in a Positive Theory. [Citation Graph (0, 0)][DBLP] Math. Log. Q., 1997, v:43, n:, pp:369-377 [Journal]