@article{ChengHartmannGuptaetal.2009,
  author    = {Fuxia Cheng and Stefanie Hartmann and Mayetri Gupta and Joseph G. Ibrahim and Todd J. Vision},
  title     = {A hierarchical model for incomplete alignments in phylogenetic inference},
  doi       = {10.1093/bioinformatics/btp015},
  url       = {http://bioinformatics.oxfordjournals.org/},
  year      = {2009},
}