i came cross this book while searching for hash bucket. http://www.faqs.org/docs/perl5int/ written by Simon Cozens on 2001.
seems to be a good book and It would be nice to be included in "online library" on Perl.org, either link or fullcopy.
licence looks okay too.
This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at http://www.opencontent.org/openpub/).