@article{MAT_1969_13_2_a1,
     author = {D. Mumford},
     title = {Picard groups of moduli problems},
     journal = {Matematika},
     pages = {26--63},
     publisher = {mathdoc},
     volume = {13},
     number = {2},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MAT_1969_13_2_a1/}
}