- Author: Raniero Cantalamessa
- Language: Spanish, Castilian
- Year: 2015
- Author: Robert M. Mond
- Language: Spanish
- Year: 2011
- Author: Obispo de Utrecht Adelbold, Alberto de Metz, Obispo Burcardo de Worms, Santo Enrique Emperador, Migne Jacques-Paul, Santo Romualdo
- Language: Latin
- Year: 1880
- Author: Floro Drepanio, de Ferrieres Loup, Lupo Servato, Migne Jacques-Paul, Papa Nicols̀ I
- Language: Latin
- Year: 1880