@article{IM_1989__95_3_143643,
     author = {John F. Carlson},
     title = {Exponents of modules and maps.},
     journal = {Inventiones mathematicae},
     pages = {13--24},
     year = {1989},
     volume = {95},
     number = {3},
     zbl = {0668.20041},
     url = {http://geodesic.mathdoc.fr/item/IM_1989__95_3_143643/}
}