APA (7th ed.) Citation

John XXIII, P. (1959). A letter from His Holiness, Pope John XXIII. Servants of the Holy Paraclete.

Chicago Style (17th ed.) Citation

John XXIII, Pope. A Letter from His Holiness, Pope John XXIII. Randolph, Vt.: Servants of the Holy Paraclete, 1959.

MLA (8th ed.) Citation

John XXIII, Pope. A Letter from His Holiness, Pope John XXIII. Servants of the Holy Paraclete, 1959.

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