This series (originally published in from 1886 -1922 in 55 volumes) is a consolidation of the history and text of hymns of the Catholic Church, 500 - 1400...

Huge "collection of all catholic available texts, declared of public knowledge, written in the main Christianity’s languages...

A collection of encyclicals (letters to groups of bishops) issued by various popes from the 13th century to the present...