The clinical investigation of a codeine resin complex; a long acting analgesic for oral administration.

@article{Cass1958TheCI,
  title={The clinical investigation of a codeine resin complex; a long acting analgesic for oral administration.},
  author={L J Cass and W S Frederik},
  journal={The New England journal of medicine},
  year={1958},
  volume={259 23},
  pages={1108-11}
}