@article{GDZPPN00124826X,
title = {When is a functionally free algebra free?},
journal = {Semigroup forum},
volume = {4},
year = {1972},
pages = {177-184},
zbl = {0255.08004},
url = {http://dml.mathdoc.fr/item/GDZPPN00124826X}
}
Evans, T. When is a functionally free algebra free?. Semigroup forum, Tome 4 (1972) pp. 177-184. http://gdmltest.u-ga.fr/item/GDZPPN00124826X/