@article{10_4064_aa117_1_3,
     author = {John Simons and Benne de Weger},
     title = {Theoretical and computational bounds for
 $m$-cycles of the $3n+1$-problem},
     journal = {Acta Arithmetica},
     pages = {51--70},
     publisher = {mathdoc},
     volume = {117},
     number = {1},
     year = {2005},
     doi = {10.4064/aa117-1-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa117-1-3/}
}