BibTeX:
@incollection{Various,
  author = {Various},
  title = {An Appeal to the Esperantists of Edinburgh},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/esperanto},
}

APA:
Various. An Appeal to the Esperantists of Edinburgh. In *bahaistories.com archive*.

MLA:
Various. "An Appeal to the Esperantists of Edinburgh." *bahaistories.com archive*, n.d..

Chicago:
Various. "An Appeal to the Esperantists of Edinburgh." In *bahaistories.com archive*, n.d..