@article{10_4064_aa117_3_3,
     author = {Kell Cheng and Hugh Williams},
     title = {Some results concerning certain
 periodic continued fractions},
     journal = {Acta Arithmetica},
     pages = {247--264},
     publisher = {mathdoc},
     volume = {117},
     number = {3},
     year = {2005},
     doi = {10.4064/aa117-3-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa117-3-3/}
}