BibTeX:
@incollection{BahChronicleseditors,
  author = {Bahá'í Chronicles editors},
  title = {Siyyid Isma’il},
  booktitle = {Bahá'í Chronicles},
  url = {https://bahaichronicles.org/siyyid-ismail/},
}

APA:
Bahá'í Chronicles editors. Siyyid Isma’il. In *Bahá'í Chronicles*.

MLA:
Bahá'í Chronicles editors. "Siyyid Isma’il." *Bahá'í Chronicles*, n.d..

Chicago:
Bahá'í Chronicles editors. "Siyyid Isma’il." In *Bahá'í Chronicles*, n.d..