@article{10_4064_aa118_4_1,
     author = {Greg Martin and Carl Pomerance},
     title = {The iterated {Carmichael} $\lambda $-function
 and the number of cycles of the power generator},
     journal = {Acta Arithmetica},
     pages = {305--335},
     publisher = {mathdoc},
     volume = {118},
     number = {4},
     year = {2005},
     doi = {10.4064/aa118-4-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa118-4-1/}
}