APA

Hellwig M., . (1981). Understanding Catholicism. New York: Paulist Press.

Chicago

Hellwig Monika, . 1981. Understanding Catholicism. New York: Paulist Press.

Harvard

Hellwig M., . (1981). Understanding Catholicism. New York: Paulist Press.

MLA

Hellwig Monika, . Understanding Catholicism. New York: Paulist Press. 1981.