APA (7th ed.) Citation

Petrus Alfonsi, Jones, J. R., & Keller, J. E. (1969). The scholar's guide. Pontifical Institute of Mediaeval Studies.

Chicago Style (17th ed.) Citation

Petrus Alfonsi, Joseph Ramon Jones, and John Esten Keller. The Scholar's Guide. Toronto: Pontifical Institute of Mediaeval Studies, 1969.

MLA (9th ed.) Citation

Petrus Alfonsi, et al. The Scholar's Guide. Pontifical Institute of Mediaeval Studies, 1969.