APA (7th ed.) Citation

Boyle, L. E., & Boyle, L. E. (2001). A survey of the Vatican archives and of its medieval holdings Subsidia mediaevalia.

Chicago Style (17th ed.) Citation

Boyle, Leonard Eugene, and Leonard E. Boyle. "A Survey of the Vatican Archives and of Its Medieval Holdings." Subsidia Mediaevalia 2001.

MLA (8th ed.) Citation

Boyle, Leonard Eugene, and Leonard E. Boyle. "A Survey of the Vatican Archives and of Its Medieval Holdings." Subsidia Mediaevalia, 2001.

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