%0 Journal Article %A Chen, Hui-Xiang %T Cleft extensions for a Hopf algebrakq[X,X−1, Y] %J Glasgow mathematical journal %D 1998 %P 147-160 %V 40 %N 2 %U http://geodesic.mathdoc.fr/articles/10.1017/S0017089500032468/ %R 10.1017/S0017089500032468 %F 10_1017_S0017089500032468