@misc{indiciaea9f5a409ea5b,
  title = {George Engelmann : botanical notebook 7 : Echinocactus, Echinopsis, and Cereus — Illustration, [No.] 1756},
  url = {https://www.biodiversitylibrary.org/page/56147444},
  note = {Source identifier: page-56147444}
}