TY - JOUR AU - Chen, Hui-Xiang TI - Cleft extensions for a Hopf algebrakq[X,X−1, Y] JO - Glasgow mathematical journal PY - 1998 SP - 147 EP - 160 VL - 40 IS - 2 UR - http://geodesic.mathdoc.fr/articles/10.1017/S0017089500032468/ DO - 10.1017/S0017089500032468 ID - 10_1017_S0017089500032468 ER -