@article{1183740200,
author = {Bunder, M. W. and Seldin, Jonathan P.},
title = {Some Anomalies in Fitch's System $QD$},
journal = {J. Symbolic Logic},
volume = {43},
number = {1},
year = {1978},
pages = { 247-249},
language = {en},
url = {http://dml.mathdoc.fr/item/1183740200}
}
Bunder, M. W.; Seldin, Jonathan P. Some Anomalies in Fitch's System $QD$. J. Symbolic Logic, Tome 43 (1978) no. 1, pp. 247-249. http://gdmltest.u-ga.fr/item/1183740200/