@article{SM_1989_62_1_a2,
     author = {V. N. Gerasimov},
     title = {The group of units of a~free product of rings},
     journal = {Sbornik. Mathematics},
     pages = {41--63},
     publisher = {mathdoc},
     volume = {62},
     number = {1},
     year = {1989},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1989_62_1_a2/}
}