APA (7th ed.) Citation

Haar, S. C. (2003). Simon Magus: The first Gnostic? Walter de Gruyter.

Chicago Style (17th ed.) Citation

Haar, Stephen Charles. Simon Magus: The First Gnostic? Berlin ; New York: Walter de Gruyter, 2003.

MLA (9th ed.) Citation

Haar, Stephen Charles. Simon Magus: The First Gnostic? Walter de Gruyter, 2003.