@article{GDZPPN002351250, title = {An Extremal Problem Involving Functions and Their Inverses.}, journal = {Mathematica Scandinavica}, volume = {28}, year = {1971}, pages = {328-336}, zbl = {0235.49007}, url = {http://dml.mathdoc.fr/item/GDZPPN002351250} }
Diamond, H.G.; Albrecht, F. An Extremal Problem Involving Functions and Their Inverses.. Mathematica Scandinavica, Tome 28 (1971) pp. 328-336. http://gdmltest.u-ga.fr/item/GDZPPN002351250/