APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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

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