BibTeX:
@incollection{LouisGGregory1911,
  author = {Louis G. Gregory},
  title = {The Shrine of the Báb on Mount Carmel: Gregory's Visit},
  booktitle = {The Heavenly Vista: The Pilgrimage of Louis G. Gregory},
  year = {1911},
  url = {https://bahai-library.com/gregory_heavenly_vista},
}

APA:
Louis G. Gregory. (1911). The Shrine of the Báb on Mount Carmel: Gregory's Visit. In *The Heavenly Vista: The Pilgrimage of Louis G. Gregory*.

MLA:
Louis G. Gregory. "The Shrine of the Báb on Mount Carmel: Gregory's Visit." *The Heavenly Vista: The Pilgrimage of Louis G. Gregory*, 1911.

Chicago:
Louis G. Gregory. "The Shrine of the Báb on Mount Carmel: Gregory's Visit." In *The Heavenly Vista: The Pilgrimage of Louis G. Gregory*, 1911.