BibTeX:
@incollection{Various,
  author = {Various},
  title = {Koae and the Tropic Bird},
  booktitle = {Baha'i Stories for Children},
  url = {https://bahaistoriesforchildren.blogspot.com/2017/07/koae.html},
}

APA:
Various. Koae and the Tropic Bird. In *Baha'i Stories for Children*.

MLA:
Various. "Koae and the Tropic Bird." *Baha'i Stories for Children*, n.d..

Chicago:
Various. "Koae and the Tropic Bird." In *Baha'i Stories for Children*, n.d..