%0 Journal Article %A A. V. Tsiganov %T Two integrable systems with integrals of motion of degree four %J Teoretičeskaâ i matematičeskaâ fizika %D 2016 %P 443-455 %V 186 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_2016_186_3_a6/ %G ru %F TMF_2016_186_3_a6