@article{10_4153_CJM_2009_058_0,
     author = {Davidson, Kenneth R. and Yang, Dilian},
     title = {Periodicity in {Rank} 2 {Graph} {Algebras}},
     journal = {Canadian journal of mathematics},
     pages = {1239--1261},
     year = {2009},
     volume = {61},
     number = {6},
     doi = {10.4153/CJM-2009-058-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2009-058-0/}
}