@article{YiW09,
  title = {++-},
  author = {Lei Yi and Baoyindureng Wu},
  year = {2009},
  url = {http://ajc.maths.uq.edu.au/pdf/44/ajc_v44_p037.pdf},
  researchr = {https://researchr.org/publication/YiW09},
  cites = {0},
  citedby = {0},
  journal = {Australasian J. Combinatorics},
  volume = {44},
  pages = {37-42},
}