@article{1093958619, author = {Massey, Gerald J.}, title = {An extension of Venn diagrams.}, journal = {Notre Dame J. Formal Logic}, volume = {7}, number = {1}, year = {1966}, pages = { 239-250}, language = {en}, url = {http://dml.mathdoc.fr/item/1093958619} }
Massey, Gerald J. An extension of Venn diagrams.. Notre Dame J. Formal Logic, Tome 7 (1966) no. 1, pp. 239-250. http://gdmltest.u-ga.fr/item/1093958619/