Inkscape: Guide to a Vector Drawing Program

"This book serves as both a textbook and a reference for using Inkscape to produce high-quality drawings. It includes a series of tutorials followed by chapters that cover completely each facet of the Inkscape program. The book is full of tips and notes to enable the user to make the best use of the program."

Inkscape: Guide to a Vector Drawing Program at http://tavmjong.free.fr/INKSCAPE/MANUAL/html/.

The Ultimate Guide To Cloning In Photoshop

"Photoshop’s wide array of cloning tools is the cause of many of the absolute best and worst works created with the application. In a skilled and experienced hand, these tools lead to phenomenal results. In the hands of a careless artist, Photoshop cloning can be disastrous to the credibility of the result. This article introduces the several cloning tools available in Photoshop and goes over the proper usage and best practices of each."

At http://www.smashingmagazine.com/2010/03/30/the-ultimate-guide-to-cloning-in-photoshop/.