BibTeX:
@incollection{Various,
  author = {Various},
  title = {The following account occurred in the Siyah-Chal prison in Teheran},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/martyrs-attitudes},
}

APA:
Various. The following account occurred in the Siyah-Chal prison in Teheran. In *bahaistories.com archive*.

MLA:
Various. "The following account occurred in the Siyah-Chal prison in Teheran." *bahaistories.com archive*, n.d..

Chicago:
Various. "The following account occurred in the Siyah-Chal prison in Teheran." In *bahaistories.com archive*, n.d..