@misc{indiciae44910ae17583,
  title = {Early and Middle Cambrian trilobites from Antarctica},
  author = {A. R. Palmer and C.G. Gatehouse},
  year = {1972},
  doi = {10.3133/pp456d},
  url = {https://pubs.usgs.gov/publication/pp456D},
  note = {Source identifier: pp456D}
}