APA (7th ed.) Citation

Gregory, O. (1822). Letters to a friend, on the evidences, doctrines, and duties of the Christian religion (4th London edition.). The American tract society.

Chicago Style (17th ed.) Citation

Gregory, Olinthus. Letters to a Friend, on the Evidences, Doctrines, and Duties of the Christian Religion. 4th London edition. New York: The American tract society, 1822.

MLA (9th ed.) Citation

Gregory, Olinthus. Letters to a Friend, on the Evidences, Doctrines, and Duties of the Christian Religion. 4th London edition. The American tract society, 1822.

Warning: These citations may not always be 100% accurate.