BibTeX:
@incollection{RhyyihKhnum1969,
  author = {Rúhíyyih Khánum},
  title = {Left Behind at Naples},
  booktitle = {The Priceless Pearl},
  year = {1969},
}

APA:
Rúhíyyih Khánum. (1969). Left Behind at Naples. In *The Priceless Pearl*.

MLA:
Rúhíyyih Khánum. "Left Behind at Naples." *The Priceless Pearl*, 1969.

Chicago:
Rúhíyyih Khánum. "Left Behind at Naples." In *The Priceless Pearl*, 1969.