BibTeX:
@incollection{Various,
  author = {Various},
  title = {Zylpha Gray's Question},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/underground-railway},
}

APA:
Various. Zylpha Gray's Question. In *bahaistories.com archive*.

MLA:
Various. "Zylpha Gray's Question." *bahaistories.com archive*, n.d..

Chicago:
Various. "Zylpha Gray's Question." In *bahaistories.com archive*, n.d..