Reader's Digest Association. (1996). Great mysteries of the 20th century. Reader's Digest.
Chicago Style (17th ed.) CitationReader's Digest Association. Great Mysteries of the 20th Century. Pleasantville: Reader's Digest, 1996.
MLA (9th ed.) CitationReader's Digest Association. Great Mysteries of the 20th Century. Reader's Digest, 1996.
Warning: These citations may not always be 100% accurate.