Bibliotheca Orientalis Clementino-Vaticana (4-volume set)

The 4,000-page Bibliotheca Orientalis Clementino-Vaticana is described as "the first and best encyclopedia for the study of early Syriac Christian literature" by The Blackwell Dictionary of Eastern Christianity. Indeed, after almost 300 years from its first appearance, BO (as it is widely known) remains the unrivaled resource on Syriac literature. The author, who comes from a Syriac Maronite tradition, was prefect of the Vatican library where he compiled this encyclopedia. It contains ca. 3,000 pages of Syriac texts with Latin translation.