@article{1117559008, author = {Henkin, Leon}, title = {Extending Boolean operations.}, journal = {Pacific J. Math.}, volume = {35}, number = {3}, year = {1970}, pages = { 723-752}, language = {en}, url = {http://dml.mathdoc.fr/item/1117559008} }
Henkin, Leon. Extending Boolean operations.. Pacific J. Math., Tome 35 (1970) no. 3, pp. 723-752. http://gdmltest.u-ga.fr/item/1117559008/