@article{CM_1990__74_3_327_0,
     author = {Yang, Zi-Xiao and Li, Bu-Xi},
     title = {On restricted derivative approximation},
     journal = {Compositio Mathematica},
     pages = {327--331},
     publisher = {Kluwer Academic Publishers},
     volume = {74},
     number = {3},
     year = {1990},
     mrnumber = {1055699},
     zbl = {0697.41002},
     language = {en},
     url = {http://www.numdam.org/item/CM_1990__74_3_327_0/}
}