@article{10_4153_CJM_1989_037_3,
     author = {Powers, Victoria},
     title = {Finite {Spaces} of {Signatures}},
     journal = {Canadian journal of mathematics},
     pages = {808--829},
     year = {1989},
     volume = {41},
     number = {5},
     doi = {10.4153/CJM-1989-037-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1989-037-3/}
}