@article{10_37236_933,
     author = {Gregg Musiker and James Propp},
     title = {Combinatorial interpretations for rank-two cluster algebras of affine type.},
     journal = {The electronic journal of combinatorics},
     year = {2007},
     volume = {14},
     doi = {10.37236/933},
     zbl = {1140.05053},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/933/}
}