@article{JIS_2003__6_4_a0,
     author = {Iannucci,  Douglas E. and Deng,  Moujie and Cohen,  Graeme L.},
     title = {On perfect totient numbers},
     journal = {Journal of integer sequences},
     year = {2003},
     volume = {6},
     number = {4},
     zbl = {1069.11001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2003__6_4_a0/}
}