Gaya APA
Cardijn, J.
(1955).
Challenge to action. Ed. & introd. by Eugene Langdale.
.
Chicago:
Fides Publ.
Gaya MLA
Cardijn, Joseph.
"Challenge to action. Ed. & introd. by Eugene Langdale. ".
Chicago:
Fides Publ,
1955.
Buku.