History - Immutemur habitu

Feb 28, 2022 (fkchaud)

Added Graduale Romanum 1974 as a source

sources
[{"chant_id":"313","source":"2","page":"85","sequence":"1","extent":"1"},{"chant_id":"313","source":"3","page":"523","sequence":"1","extent":"1"},{"chant_id":"313","source":"4","page":"65","sequence":"1","extent":"1"}]