Schaff, P. (1987). The principle of Protestantism: Philip Schaff. American religious thought of the eighteenth and 19th centuries.
Chicago Style (17th ed.) CitationSchaff, Philip. "The Principle of Protestantism: Philip Schaff." American Religious Thought of the Eighteenth and 19th Centuries 1987.
MLA (8th ed.) CitationSchaff, Philip. "The Principle of Protestantism: Philip Schaff." American Religious Thought of the Eighteenth and 19th Centuries, 1987.
Warning: These citations may not always be 100% accurate.