BibTeX:
@incollection{MrzMamdiZarqn1998,
  author = {Mírzá Maḥmúd-i-Zarqání},
  title = {What White Teeth It Has},
  booktitle = {Mahmúd's Diary},
  year = {1998},
  publisher = {George Ronald},
  url = {https://bahai-library.com/zarqani_mahmuds_diary},
}

APA:
Mírzá Maḥmúd-i-Zarqání. (1998). What White Teeth It Has. In *Mahmúd's Diary*. George Ronald.

MLA:
Mírzá Maḥmúd-i-Zarqání. "What White Teeth It Has." *Mahmúd's Diary*, George Ronald, 1998.

Chicago:
Mírzá Maḥmúd-i-Zarqání. "What White Teeth It Has." In *Mahmúd's Diary*, George Ronald, 1998.