Voir la notice de l'article provenant de la source Math-Net.Ru
@article{TRSPY_1980_152_a6, author = {M. D. Kovalev}, title = {A~characteristic property of a~disc}, journal = {Informatics and Automation}, pages = {124--137}, publisher = {mathdoc}, volume = {152}, year = {1980}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TRSPY_1980_152_a6/} }
M. D. Kovalev. A~characteristic property of a~disc. Informatics and Automation, Geometry of positive quadratic forms, Tome 152 (1980), pp. 124-137. http://geodesic.mathdoc.fr/item/TRSPY_1980_152_a6/