@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/