@article{10_4153_CMB_2014_057_x,
     author = {Hasegawa, Kei},
     title = {Essential {Commutants} of {Semicrossed} {Products}},
     journal = {Canadian mathematical bulletin},
     pages = {91--104},
     year = {2015},
     volume = {58},
     number = {1},
     doi = {10.4153/CMB-2014-057-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-2014-057-x/}
}