@article{1077477505, author = {Berkovitz, Leonard D.}, title = {Double Sturm-Liouville expansions}, journal = {Duke Math. J.}, volume = {19}, number = {1}, year = {1952}, pages = { 567-574}, language = {en}, url = {http://dml.mathdoc.fr/item/1077477505} }
Berkovitz, Leonard D. Double Sturm-Liouville expansions. Duke Math. J., Tome 19 (1952) no. 1, pp. 567-574. http://gdmltest.u-ga.fr/item/1077477505/