@article{10_4153_CJM_1967_001_x,
     author = {Barback, Joseph},
     title = {Double {Series} of {Isols}},
     journal = {Canadian journal of mathematics},
     pages = {1--15},
     year = {1967},
     volume = {19},
     number = {1},
     doi = {10.4153/CJM-1967-001-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1967-001-x/}
}