@article{1183742382, author = {Buechler, Steven}, title = {On Nontrivial Types of $U$-Rank}, journal = {J. Symbolic Logic}, volume = {52}, number = {1}, year = {1987}, pages = { 548-551}, language = {en}, url = {http://dml.mathdoc.fr/item/1183742382} }
Buechler, Steven. On Nontrivial Types of $U$-Rank. J. Symbolic Logic, Tome 52 (1987) no. 1, pp. 548-551. http://gdmltest.u-ga.fr/item/1183742382/