Reference: Campbell 1973

Campbell, Lyle. 1973. On glottalic consonants. International Journal of American Linguistics 39(1). 44–46. Indiana University.

@article{campbell1973glottalic,
  author    = {Campbell, Lyle},
  journal   = {International Journal of American Linguistics},
  number    = {1},
  pages     = {44–46},
  publisher = {Indiana University},
  title     = {On glottalic consonants},
  volume    = {39},
  year      = {1973}
}