The definitive biography of Fritz Kolbe, code-named George Wood, was written by Lucas Delattre and published in 2003.
Fritz Kolbe, Un Espion Au Coeur du IIIème Reich was published by French publisher Denoël (catalogue listing). The book has been translated into German, English (Grove Atlantic) and several other languages.
Lucas Delattre was a journalist for the French newspaper Le Monde and was the Germany correspondant from 1989 to 1997. Later he served as assistant editor-in-chief at Le Monde des Debats. Lucas now lives in Paris.
Here Lucas discusses his book (in French).
George Wood Movie Limited holds the film rights to this book.