Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{ELMA_1972__27_141078, author = {J. Steinig}, title = {Some {Trigonometric} {Inequalities.}}, journal = {Elemente der Mathematik}, pages = {121--128}, publisher = {mathdoc}, volume = {27}, year = {1972}, zbl = {0266.50007}, url = {http://geodesic.mathdoc.fr/item/ELMA_1972__27_141078/} }
J. Steinig. Some Trigonometric Inequalities.. Elemente der Mathematik, Tome 27 (1972), pp. 121-128. http://geodesic.mathdoc.fr/item/ELMA_1972__27_141078/