@article{8195,
  author = {G. Natanson},
  title = {Analytical formula for direction cosines of the Eckart frame of a planar molecule},
  year = {1985},
  journal = {Chemical Physics Letters},
  volume = {121},
  pages = {343-346},
  month = {Jan-11-1985},
  issn = {00092614},
  url = {http://linkinghub.elsevier.com/retrieve/pii/0009261485871906},
  doi = {10.1016/0009-2614(85)87190-6},
}