Reader's Digest (U.S. Edition). Reader's Digest Association.
Cita Chicago (17th ed.)Reader's Digest (U.S. Edition). Pleasantville, N.Y: Reader's Digest Association.
Cita MLA (9th ed.)Reader's Digest (U.S. Edition). Reader's Digest Association.
Atenció: Aquestes cites poden no estar 100% correctes.