@article{10_1017_S0017089500032468,
     author = {Chen, Hui-Xiang},
     title = {Cleft extensions for a {Hopf} {algebrakq[X,X\ensuremath{-}1,} {Y]}},
     journal = {Glasgow mathematical journal},
     pages = {147--160},
     year = {1998},
     volume = {40},
     number = {2},
     doi = {10.1017/S0017089500032468},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500032468/}
}