Covell, R. R. (1973). An extension seminary primer (2ª ed.). William Carey Library.
Cita Chicago (17th ed.)Covell, Ralph R. An Extension Seminary Primer. 2ª ed. William Carey Library, 1973.
Cita MLA (9th ed.)Covell, Ralph R. An Extension Seminary Primer. 2ª ed. William Carey Library, 1973.
Atenció: Aquestes cites poden no estar 100% correctes.