BibTeX:
@incollection{StaroftheWestEditors1919,
  author = {Star of the West Editors},
  title = {Elizabeth Stewart's Wartime Letter from Tehran},
  booktitle = {Star of the West},
  year = {1919},
  publisher = {Bahai News Service},
  url = {https://bahai.works/Star_of_the_West/Volume_10/Issue_3/Text},
}

APA:
Star of the West Editors. (1919). Elizabeth Stewart's Wartime Letter from Tehran. In *Star of the West*. Bahai News Service.

MLA:
Star of the West Editors. "Elizabeth Stewart's Wartime Letter from Tehran." *Star of the West*, Bahai News Service, 1919.

Chicago:
Star of the West Editors. "Elizabeth Stewart's Wartime Letter from Tehran." In *Star of the West*, Bahai News Service, 1919.