Voir la notice de l'article provenant de la source eLibrary of Mathematical Institute of the Serbian Academy of Sciences and Arts
@article{PIM_1956_S_S_IX_09_a6, author = {T. P. Angelitch}, title = {Eine {Bemerkung} {Zu} {Den} {Gleichungen} {Von} {Beltraimi-Michell}}, journal = {Publications de l'Institut Math\'ematique}, pages = {93 }, publisher = {mathdoc}, volume = {_S_S_IX}, number = {09}, year = {1956}, url = {http://geodesic.mathdoc.fr/item/PIM_1956_S_S_IX_09_a6/} }
T. P. Angelitch. Eine Bemerkung Zu Den Gleichungen Von Beltraimi-Michell. Publications de l'Institut Mathématique, _S_S_IX (1956) no. 09, p. 93 . http://geodesic.mathdoc.fr/item/PIM_1956_S_S_IX_09_a6/