@article{10_4153_CJM_1973_060_4,
     author = {Klarner, D. A. and Rivest, R. L.},
     title = {A {Procedure} for {Improving} the {Upper} {Bound} for the {Number} of {n-Ominoes}},
     journal = {Canadian journal of mathematics},
     pages = {585--602},
     year = {1973},
     volume = {25},
     number = {3},
     doi = {10.4153/CJM-1973-060-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1973-060-4/}
}