@article{MM2_1980__32_154734,
     author = {W. Fulton and Kent Johnson},
     title = {Canonical {Classes} on {Singular} {Varieties.}},
     journal = {Manuscripta mathematica},
     pages = {381--390},
     year = {1980},
     volume = {32},
     zbl = {0451.14001},
     url = {http://geodesic.mathdoc.fr/item/MM2_1980__32_154734/}
}