@article{GDZPPN002537311,
title = {A proof and an extension of a theorem of G. Birkhoff.},
journal = {Publications de l'Institut Math\'ematique [Elektronische Ressource]},
volume = {38},
year = {1978},
pages = {137-140},
zbl = {0384.06005},
url = {http://dml.mathdoc.fr/item/GDZPPN002537311}
}
Milic, S. A proof and an extension of a theorem of G. Birkhoff.. Publications de l'Institut Mathématique [Elektronische Ressource], Tome 38 (1978) pp. 137-140. http://gdmltest.u-ga.fr/item/GDZPPN002537311/