@article{1093888029,
author = {Butrick, Richard},
title = {A deduction rule for ${\rm VBTO}($ $)^n\_{i=1}$.},
journal = {Notre Dame J. Formal Logic},
volume = {18},
number = {1},
year = {1977},
pages = { 510-512},
language = {en},
url = {http://dml.mathdoc.fr/item/1093888029}
}
Butrick, Richard. A deduction rule for ${\rm VBTO}($ $)^n_{i=1}$.. Notre Dame J. Formal Logic, Tome 18 (1977) no. 1, pp. 510-512. http://gdmltest.u-ga.fr/item/1093888029/