Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{ELMA_1954__9_140606, author = {W. Klepper}, title = {\"Uber die nat\"urliche {Gleichung} {R(s)} = ...a (... + cos...).}, journal = {Elemente der Mathematik}, pages = {56--63}, publisher = {mathdoc}, volume = {9}, year = {1954}, zbl = {0056.14901}, url = {http://geodesic.mathdoc.fr/item/ELMA_1954__9_140606/} }
W. Klepper. Über die natürliche Gleichung R(s) = ...a (... + cos...).. Elemente der Mathematik, Tome 9 (1954), pp. 56-63. http://geodesic.mathdoc.fr/item/ELMA_1954__9_140606/