BibTeX:
@incollection{Various,
  author = {Various},
  title = {Calm to the Very End},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/peacefulness},
}

APA:
Various. Calm to the Very End. In *bahaistories.com archive*.

MLA:
Various. "Calm to the Very End." *bahaistories.com archive*, n.d..

Chicago:
Various. "Calm to the Very End." In *bahaistories.com archive*, n.d..