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Secret codes
Title:
Secret codes
Personal Author EPSB:
Summary:
Presents several easy codes with messages to decode and directions for making and writing with invisible ink and devising one's own code.
Year Published:
1980
Series:
Physical Description:
32 p. : col. ill. ; 26 cm.
Subject:
Added Author:
ISBN:
9780531041468
Publisher:
New York : F. Watts, 1980.