@article{MZ_1972__129_171826,
     author = {Wolmer V. Vasconcelos},
     title = {Simple {Flat} {Extensions.} {II.}},
     journal = {Mathematische Zeitschrift},
     pages = {157--162},
     publisher = {mathdoc},
     volume = {129},
     year = {1972},
     zbl = {0236.13004},
     url = {http://geodesic.mathdoc.fr/item/MZ_1972__129_171826/}
}