Information and statistical data
ARDA - Association for Religion Data Archives. The Religion and State Project.
Catholic Yearbook - Contacts of the Catholic Church in Portugal.
INE - National Institute of Statistics
Pew Research Center, The Global Religious Landscape, 2012.
PORDATA : database of contemporary Portugal.
Fatima Sanctuary: statistics on the pilgrimage to the sanctuary.
Portuguese Catholic University - Center for Studies and Opinion and Centre for the Study of Religions and Cultures: Study " Religious Identities in Portugal: Representations, Values and Practices", 2012.