@article{DBLP:journals/iandc/GallierNPS90,
  author    = {Jean H. Gallier and
               Paliath Narendran and
               David A. Plaisted and
               Wayne Snyder},
  title     = {Rigid E-Unification: NP-Completeness and Applications to
               Equational Matings},
  journal   = {Inf. Comput.},
  volume    = {87},
  number    = {1/2},
  year      = {1990},
  pages     = {129-195},
  ee        = {http://dx.doi.org/10.1016/0890-5401(90)90061-L},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}