here is a link to a QB discussion of the block
http://www.quiltingboard.com/main-f1...s-t116567.html
and here is a link to the book by marci baker
http://www.amazon.com/ABC-3-D-Tumbli.../dp/0965143961
i did her original tumbling blocks by the strip method and it was easy to follow. i've not done the 3-d ones