@article{10_4153_CJM_1975_002_x,
     author = {Fieldhouse, David J.},
     title = {Absolute {Purity}},
     journal = {Canadian journal of mathematics},
     pages = {6--10},
     year = {1975},
     volume = {27},
     number = {1},
     doi = {10.4153/CJM-1975-002-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1975-002-x/}
}