Reference: de Angulo and Freeland 1930

Angulo, Jaime de & Lucy S. Freeland. 1930. The Achumawi Language. International Journal of American Linguistics 6(2). 77–120.

@article{deangulo1930achumawi,
  author  = {Jaime de Angulo and Lucy S. Freeland},
  journal = {International Journal of American Linguistics},
  number  = {2},
  pages   = {77–120},
  title   = {The Achumawi Language},
  volume  = {6},
  year    = {1930}
}