@article{MZ_1967__102_170878,
     author = {Richard G. Swan},
     title = {The {Number} of {Generators} of a {Module.}},
     journal = {Mathematische Zeitschrift},
     pages = {318--322},
     year = {1967},
     volume = {102},
     zbl = {0156.27403},
     url = {http://geodesic.mathdoc.fr/item/MZ_1967__102_170878/}
}