@misc{indiciaeaa813a33b6bb,
  title = {George Engelmann : botanical notebook 9 : Echinocereus, Cereus, Eulychnia, Pilocereus — Illustration, [No.] 1981},
  url = {https://www.biodiversitylibrary.org/page/56210033},
  note = {Source identifier: page-56210033}
}