BibTeX:
@incollection{StaroftheWestEditors1921,
  author = {Star of the West Editors},
  title = {A Convention for Oneness: The Word Spoken in Washington, 1921},
  booktitle = {Star of the West},
  year = {1921},
  publisher = {Bahai News Service},
  url = {https://bahai-library.com/star_of_the_west_volume_12},
}

APA:
Star of the West Editors. (1921). A Convention for Oneness: The Word Spoken in Washington, 1921. In *Star of the West*. Bahai News Service.

MLA:
Star of the West Editors. "A Convention for Oneness: The Word Spoken in Washington, 1921." *Star of the West*, Bahai News Service, 1921.

Chicago:
Star of the West Editors. "A Convention for Oneness: The Word Spoken in Washington, 1921." In *Star of the West*, Bahai News Service, 1921.