@article{10_4153_CJM_1970_013_8,
     author = {Wichman, Michael},
     title = {The {Width} of a {Module}},
     journal = {Canadian journal of mathematics},
     pages = {102--115},
     year = {1970},
     volume = {22},
     number = {1},
     doi = {10.4153/CJM-1970-013-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1970-013-8/}
}