@article{ZNSL_2011_388_a8,
     author = {A. V. Prokopchuk and V. I. Yanchevskiǐ},
     title = {Invariant subalgebras of involutorial quaternion division algebras},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {196--209},
     publisher = {mathdoc},
     volume = {388},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2011_388_a8/}
}