@article{MAN_1990__287_1_164695,
     author = {Hartwig von Essen},
     title = {Nonflat deformations of modules and isolated singularities.},
     journal = {Mathematische Annalen},
     pages = {413--428},
     publisher = {mathdoc},
     volume = {287},
     number = {1},
     year = {1990},
     zbl = {0707.14002},
     url = {http://geodesic.mathdoc.fr/item/MAN_1990__287_1_164695/}
}