@article{10_4064_aa_56_1_33_53,
     author = {Jeffrey Lagarias},
     title = {The set of rational cycles for the 3x+1 problem},
     journal = {Acta Arithmetica},
     pages = {33--53},
     publisher = {mathdoc},
     volume = {56},
     number = {1},
     year = {1990},
     doi = {10.4064/aa-56-1-33-53},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-56-1-33-53/}
}