@article{CMH_1973__48_139533,
     author = {Erhard Senn},
     title = {Der {Funktor} {EXT...(.,} {R)} in endlichen, graduierten {Algebren}},
     journal = {Commentarii mathematici Helvetici},
     pages = {1--13},
     year = {1973},
     volume = {48},
     zbl = {0258.13006},
     url = {http://geodesic.mathdoc.fr/item/CMH_1973__48_139533/}
}