@article{ETNA_2005__20__a15,
     author = {Janovsk\'a, Drahoslava and Opfer, Gerhard},
     title = {Fast {Givens} transformation for quaternion valued matrices applied to {Hessenberg} reductions},
     journal = {Electronic transactions on numerical analysis},
     pages = {1--26},
     publisher = {mathdoc},
     volume = {20},
     year = {2005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2005__20__a15/}
}