@article{DMGAA_2009_29_1_a2,
     author = {Grytczuk, Aleksander and Kurzyd{\l}o, Izabela},
     title = {On the matrix negative {Pell} equation},
     journal = {Discussiones Mathematicae. General Algebra and Applications},
     pages = {35--45},
     publisher = {mathdoc},
     volume = {29},
     number = {1},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGAA_2009_29_1_a2/}
}