@article{GDZPPN002386208, title = {The Schwinger variational principles for one-dimensional quantum scattering.}, journal = {Mathematische Zeitschrift}, volume = {64}, year = {1956}, pages = {309-326}, zbl = {0070.44405}, url = {http://dml.mathdoc.fr/item/GDZPPN002386208} }
Dolph, D.L.; Ritt, R.K. The Schwinger variational principles for one-dimensional quantum scattering.. Mathematische Zeitschrift, Tome 64 (1956) pp. 309-326. http://gdmltest.u-ga.fr/item/GDZPPN002386208/