@article{100394, author = {Ludv\'\i k Jano\v s}, title = {Vyvod odnogo neravenstva dlia pervykh sobstvennykh znachenii dvukh kraevykh zadach}, journal = {Czechoslovak Mathematical Journal}, volume = {10}, year = {1960}, pages = {68-82}, zbl = {0101.06601}, mrnumber = {0116191}, language = {ru}, url = {http://dml.mathdoc.fr/item/100394} }
Janoš, Ludvík. Вывод одного неравенства для первых собственных значений двух краевых задач. Czechoslovak Mathematical Journal, Tome 10 (1960) pp. 68-82. http://gdmltest.u-ga.fr/item/100394/