@misc {IOPORT.70021392,
    author       = {Yao, Ming and Yao, Bing},
    title        = {A note on the definition of a tree},
    howpublished = {BMEI, 1-5 (2009).},
    year         = {2009},
    doi          = {10.1109/BMEI.2009.5304812},
    identifier   = {70021392},
}