@article{GDZPPN002062119, title = {Projective k-invariants}, journal = {Commentarii mathematici Helvetici}, volume = {51}, year = {1976}, pages = {259-278}, zbl = {0329.55009}, url = {http://dml.mathdoc.fr/item/GDZPPN002062119} }
Dyer, Michael N. Projective k-invariants. Commentarii mathematici Helvetici, Tome 51 (1976) pp. 259-278. http://gdmltest.u-ga.fr/item/GDZPPN002062119/