- The Ante-Nicene Fathers: Volume IX - Recently Discovered Additions to Early Christian Literature
- The Earliest Gospel; a Historical Study of the Gospel According to Mark, With a Text and English Version.
- History of Religion: A Sketch of Primitive Religious Beliefs and Practices, and of the Origin and Character of the Great Systems
- The Religions of India. Brahmanism and Buddhism...
- Paul, The Apostle Of Jesus Christ: His Life And Work, His Epistles And His Doctrine. A Contribution To The Critical History Of Primitive Christianity, Volume 1