@article{FORUM_1991__3_2_186393,
     author = {John Dauns},
     title = {Classes of {Modules.}},
     journal = {Forum mathematicum},
     pages = {327--338},
     publisher = {mathdoc},
     volume = {3},
     number = {2},
     year = {1991},
     zbl = {0727.16001},
     url = {http://geodesic.mathdoc.fr/item/FORUM_1991__3_2_186393/}
}