BibTeX:
@incollection{Various,
  author = {Various},
  title = {At the Prison Gates},
  booktitle = {Baha'i Stories for Children},
  url = {https://bahaistoriesforchildren.blogspot.com/2018/11/at-prison-gates.html},
}

APA:
Various. At the Prison Gates. In *Baha'i Stories for Children*.

MLA:
Various. "At the Prison Gates." *Baha'i Stories for Children*, n.d..

Chicago:
Various. "At the Prison Gates." In *Baha'i Stories for Children*, n.d..