Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MZ_1952__57_169305, author = {Hanfried Lenz}, title = {\"Uber {Orthogonaltrajektorien.}}, journal = {Mathematische Zeitschrift}, pages = {46--64}, publisher = {mathdoc}, volume = {57}, year = {1952}, language = {de}, url = {http://geodesic.mathdoc.fr/item/MZ_1952__57_169305/} }
Hanfried Lenz. Über Orthogonaltrajektorien.. Mathematische Zeitschrift, Tome 57 (1952), pp. 46-64. http://geodesic.mathdoc.fr/item/MZ_1952__57_169305/