@article{MZ_1988__200_3_174010,
     author = {Roger Wiegand},
     title = {Picard {Groups} of {Singular} {Affine} {Curves} over a {Perfect} {Fields.}},
     journal = {Mathematische Zeitschrift},
     pages = {301--312},
     year = {1988},
     volume = {200},
     number = {3},
     zbl = {0637.14006},
     url = {http://geodesic.mathdoc.fr/item/MZ_1988__200_3_174010/}
}