Tre pontificati : Leone 12., Pio 8., Gregorio 16 - Vercesi, Ernesto. (OLS)http://semarc/name/36890 (SEI,, 1936)
Keywords: Gregorio XVI <papa; 1765-1846>. (OLS)http://semarc/subject/3525; Leone XII <papa; 1760-1829>. (OLS)http://semarc/subject/4919; Pio VIII <papa; 1761-1830>. (OLS)http://semarc/subject/4918; Chiesa - Storia - Sec. 18.-19. (OLS)http://semarc/subject/4940