Etymological Dictionaries

Bernhard Karlgren, "Analytic Dictionary of Chinese and Sino-Japanese" (Dover reprint of 1991) ISBN 0-486-26887-X.

Rick Harbaugh's “Chinese Characters: A Genealogy and Dictionary: http://www.zhongwen.com/

Also available at http://www.Amazon.com for $18.95.

Wieger's “Chinese Characters”.