@article{ETNA_2014__41__a17,
     author = {Janovsk\'a, Drahoslava and Opfer, Gerhard},
     title = {Zeros and singular points for one-sided coquaternionic polynomials with an extension to other $R^4$ algebras},
     journal = {Electronic transactions on numerical analysis},
     pages = {133--158},
     publisher = {mathdoc},
     volume = {41},
     year = {2014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2014__41__a17/}
}