Watt, L. (1929). Catholic social principles: A commentary on the papal encyclical Rerum novarum. Burns, Oates & Washbourne ltd..
Chicago-referens (17:e uppl.)Watt, Lewis. Catholic Social Principles: A Commentary on the Papal Encyclical Rerum Novarum. London: Burns, Oates & Washbourne ltd., 1929.
MLA-referens (8:e uppl.)Watt, Lewis. Catholic Social Principles: A Commentary on the Papal Encyclical Rerum Novarum. Burns, Oates & Washbourne ltd., 1929.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.