@article{GDZPPN002055015, title = {Relations between cohomology groups in a complex.}, journal = {Commentarii mathematici Helvetici}, volume = {21}, year = {1948}, pages = {302-320}, zbl = {0031.18103}, url = {http://dml.mathdoc.fr/item/GDZPPN002055015} }
Eilenberg, Samuel. Relations between cohomology groups in a complex.. Commentarii mathematici Helvetici, Tome 21 (1948) pp. 302-320. http://gdmltest.u-ga.fr/item/GDZPPN002055015/