@article{1183738857, author = {Seldin, Jonathan P.}, title = {Equality in $\mathscr{F}\_{21}$}, journal = {J. Symbolic Logic}, volume = {38}, number = {1}, year = {1973}, pages = { 571-575}, language = {en}, url = {http://dml.mathdoc.fr/item/1183738857} }
Seldin, Jonathan P. Equality in $\mathscr{F}_{21}$. J. Symbolic Logic, Tome 38 (1973) no. 1, pp. 571-575. http://gdmltest.u-ga.fr/item/1183738857/