The Jargon File (version 4.4.7, 29 Dec 2003):

Camel Book
 n.

    Universally recognized nickname for the book Programming Perl, by Larry
    Wall and Randal L. Schwartz, O'Reilly and Associates 1991, ISBN
    0-937175-64-1 (second edition 1996, ISBN 1-56592-149-6; third edition 2000,
    0-596-00027-8, adding as authors Tom Christiansen and Jon Orwant but
    dropping Randal Schwartz). The definitive reference on Perl.