@article{GDZPPN002060132,
title = {Primitivity in torsion free cohomology Hopf algebras},
journal = {Commentarii mathematici Helvetici},
volume = {46},
year = {1971},
pages = {13-43},
zbl = {0225.57023},
url = {http://dml.mathdoc.fr/item/GDZPPN002060132}
}
Hubbuck, J.R. Primitivity in torsion free cohomology Hopf algebras. Commentarii mathematici Helvetici, Tome 46 (1971) pp. 13-43. http://gdmltest.u-ga.fr/item/GDZPPN002060132/