Mithraism (Cult of Mithras).

Images of Mithra by Philippa Adrych

Mithras. Mysteries and Inititation Rediscovered by D. Jason Cooper

Romanising Oriental Gods. Myth, Salvation, and Ethics in the Cults of Cybele, Isis, and Mithras by Jaime Alvar

The Cult of Mithras in Late Antiquity. Development, Decline, and Demise Ca. A.D. 270-430 by Walsh D.

The End of Paganism in the North-Western Provinces of the Roman Empire by Eberhard Sauer

The Mysteries of Mithras The Pagan Belief That Shaped the Christian World by Payam Nabarz, Caitlin Matthews

The Religion of the Mithras Cult in the Roman Empire: Mysteries of the Unconquered Sun by Roger Beck

The Roman Cult of Mithras The God and His Mysteries by Manfred Clauss