@article{00874302,
title = {Some characterizations of totients.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {19},
year = {1996},
pages = {209-217},
doi = {10.1155/S0161171296000312},
zbl = {0846.11005},
language = {en},
url = {http://dml.mathdoc.fr/item/00874302}
}
Haukkanen, Pentti. Some characterizations of totients.. International Journal of Mathematics and Mathematical Sciences, Tome 19 (1996) pp. 209-217. doi : 10.1155/S0161171296000312. http://gdmltest.u-ga.fr/item/00874302/