This site lists and summarises high quality research and so a disclaimer is needed at the beginning of this summary to highlight that this book has serious shortcomings. Navigating the text is difficult and the intentions of and decisions made by the interpreter are not clear. That said, this book is the only text which concentrates on and includes this amount of al Zawahiri's writings. It is for this reason only that it is included, as it may be of use to people who want to access more of al Zawahiri's writings than can be found elsewhere.
High quality works which include translations of al Zawahiri can be found in Kepel and Milelli's edited collection as well as Ibrahim's selection. Both these draw on texts from a number of al Qaeda's leaders and ideologues including al Zawahiri.