@misc{indiciae98a41c4e8c0e,
  title = {George Engelmann : botanical notebook 7 : Echinocactus, Echinopsis, and Cereus — Illustration, [No.] 1622 verso},
  url = {https://www.biodiversitylibrary.org/page/56141684},
  note = {Source identifier: page-56141684}
}