@article{10_4064_aa_28_4_387_389,
     author = {Carl Pomerance},
     title = {On composite n for which \ensuremath{\varphi}(n) | n -1},
     journal = {Acta Arithmetica},
     pages = {387--389},
     publisher = {mathdoc},
     volume = {28},
     number = {4},
     year = {1975},
     doi = {10.4064/aa-28-4-387-389},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-28-4-387-389/}
}