@article{01149588, title = {The distribution of totients.}, journal = {Electronic Research Announcements of the American Mathematical Society [electronic only]}, volume = {4}, year = {1998}, pages = {27-34}, doi = {10.1090/S1079-6762-98-00043-2}, zbl = {0888.11003}, language = {en}, url = {http://dml.mathdoc.fr/item/01149588} }
Ford, Kevin. The distribution of totients.. Electronic Research Announcements of the American Mathematical Society [electronic only], Tome 4 (1998) pp. 27-34. doi : 10.1090/S1079-6762-98-00043-2. http://gdmltest.u-ga.fr/item/01149588/