@article{10_4153_CJM_1978_102_6,
     author = {Dlab, Vlastimil and Ringel, Claus Michael},
     title = {Real {Subspaces} of a {Quaternion} {Vector} {Space}},
     journal = {Canadian journal of mathematics},
     pages = {1228--1242},
     year = {1978},
     volume = {30},
     number = {6},
     doi = {10.4153/CJM-1978-102-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1978-102-6/}
}