@article{ZhangYang1998,
  author    = {{Zhang, Zhongfu  and Yang, Shiming}},
  title     = {{Problems on mapping sequences}},
  journal   = {{Mathmedia [Shu xue chuan bo ji kan]}},
  year      = {{1998}},
  volume    = {{22}},
  pages     = {{76--88}},
}