APA (7th ed.) Citation

Petri de Ortega, O., & Ortega, P. D. Exercitium et devotiones.

Chicago Style (17th ed.) Citation

Petri de Ortega, O.S.B, and Pedro De Ortega. Exercitium Et Devotiones.

MLA (9th ed.) Citation

Petri de Ortega, O.S.B, and Pedro De Ortega. Exercitium Et Devotiones.

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