An unmatched resource for the study of liturgy, both western and eastern, Assemani’s Codex Liturgicus Ecclesiae Universae, in twelve volumes, contains texts in Latin, Greek, Coptic, Arabic, and Syriac; the non-Latin texts have translations into that language. The documents are arranged according to liturgical subject matter, and detailed tables of contents will allow the reader to find the desired texts more easily. The Assemani family played a major role in introducing European scholars to Christian literature and liturgy in Syriac and Arabic, and these volumes by Joseph Aloysius, together with those of his brother’s Bibliotheca Orientalis (also available from Gorgias Press), are the bedrock of that well-deserved reputation.