BibTeX:
@incollection{RhyyihKhnum1969,
  author = {Rúhíyyih Khánum},
  title = {The Mighty Blast of the Trumpet},
  booktitle = {The Priceless Pearl},
  year = {1969},
}

APA:
Rúhíyyih Khánum. (1969). The Mighty Blast of the Trumpet. In *The Priceless Pearl*.

MLA:
Rúhíyyih Khánum. "The Mighty Blast of the Trumpet." *The Priceless Pearl*, 1969.

Chicago:
Rúhíyyih Khánum. "The Mighty Blast of the Trumpet." In *The Priceless Pearl*, 1969.