@article{MAN_1972__196_162238,
     author = {Harvey Cohn},
     title = {Markoff {Forms} and {Primitive} {Words.}},
     journal = {Mathematische Annalen},
     pages = {8--22},
     publisher = {mathdoc},
     volume = {196},
     year = {1972},
     zbl = {0227.10018},
     url = {http://geodesic.mathdoc.fr/item/MAN_1972__196_162238/}
}