Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MAT_1972_16_1_a2, author = {R. Sakamoto}, title = {Mixed problems for hyperbolic equations. {I.~Energy} inequalities}, journal = {Matematika}, pages = {62--80}, publisher = {mathdoc}, volume = {16}, number = {1}, year = {1972}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MAT_1972_16_1_a2/} }
R. Sakamoto. Mixed problems for hyperbolic equations. I.~Energy inequalities. Matematika, Tome 16 (1972) no. 1, pp. 62-80. http://geodesic.mathdoc.fr/item/MAT_1972_16_1_a2/