@misc{indiciae1e7a38020f6a,
  title = {George Engelmann : botanical notebook 7 : Echinocactus, Echinopsis, and Cereus — Illustration, [No.] 1760},
  url = {https://www.biodiversitylibrary.org/page/56147453},
  note = {Source identifier: page-56147453}
}