@article{10_4153_CJM_1967_014_9,
     author = {Barbeau, Edward J.},
     title = {Subordinate and {Pseudo-Subordinate} {Semi-Algebras}},
     journal = {Canadian journal of mathematics},
     pages = {212--224},
     year = {1967},
     volume = {19},
     number = {1},
     doi = {10.4153/CJM-1967-014-9},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1967-014-9/}
}