Reader's Digest Association. (1996). Great mysteries of the 20th century. Reader's Digest.
Lua i Stíl Chicago (17ú heag.)Reader's Digest Association. Great Mysteries of the 20th Century. Pleasantville: Reader's Digest, 1996.
Lua MLA (9ú heag.)Reader's Digest Association. Great Mysteries of the 20th Century. Reader's Digest, 1996.
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