BibTeX:
@incollection{MrzMamdiZarqn1998,
  author = {Mírzá Maḥmúd-i-Zarqání},
  title = {The Quiet Days at Dublin: 'Abdu'l-Bahá Among the New Hampshire Hills},
  booktitle = {Mahmúd's Diary: The Diary of Mírzá Maḥmúd-i-Zarqání},
  year = {1998},
  publisher = {George Ronald},
}

APA:
Mírzá Maḥmúd-i-Zarqání. (1998). The Quiet Days at Dublin: 'Abdu'l-Bahá Among the New Hampshire Hills. In *Mahmúd's Diary: The Diary of Mírzá Maḥmúd-i-Zarqání*. George Ronald.

MLA:
Mírzá Maḥmúd-i-Zarqání. "The Quiet Days at Dublin: 'Abdu'l-Bahá Among the New Hampshire Hills." *Mahmúd's Diary: The Diary of Mírzá Maḥmúd-i-Zarqání*, George Ronald, 1998.

Chicago:
Mírzá Maḥmúd-i-Zarqání. "The Quiet Days at Dublin: 'Abdu'l-Bahá Among the New Hampshire Hills." In *Mahmúd's Diary: The Diary of Mírzá Maḥmúd-i-Zarqání*, George Ronald, 1998.