Gaya APA
Camp, R, L. (1969).
The papal ideology of social reform, a study in historical development 1878-1967. .
Leiden:
Brill.
Gaya MLA
Camp, Richard, L..
"The papal ideology of social reform, a study in historical development 1878-1967. ".
Leiden:
Brill,
1969.
Buku.