Statistical information
A presentation of the religious groups has been written by the National institute of statistic of Poland in 2014 (in Polish). The previous report had been written in 2008.
The website of the institute of Statistics of the Catholic Church (Instytut Statystyki Kościoła Katolickiego) provides information concerning religious demography; the Central Statistical Office of Poland also.
The Public Opinion Research Center (Centrum Badania Opinii Społecznej, CBOS), regularly publishes reports concerning religion.
22 April 2014