BibTeX:
@incollection{AbdulBah1982,
  author = {'Abdu'l-Bahá},
  title = {Dear Sister, Beloved of My Heart and Soul!},
  booktitle = {Bahíyyih Khánum},
  year = {1982},
  pages = {Part II, no. 4},
  url = {https://www.gutenberg.org/cache/epub/19242/pg19242-images.html},
}

APA:
'Abdu'l-Bahá. (1982). Dear Sister, Beloved of My Heart and Soul!. In *Bahíyyih Khánum* (p. Part II, no. 4).

MLA:
'Abdu'l-Bahá. "Dear Sister, Beloved of My Heart and Soul!." *Bahíyyih Khánum*, 1982, p. Part II, no. 4.

Chicago:
'Abdu'l-Bahá. "Dear Sister, Beloved of My Heart and Soul!." In *Bahíyyih Khánum*, Part II, no. 4. 1982.