From the reviews of the second edition: "Satisfyingly heavy and a pleasure to handle ... Volume 2 of the Second Edition of this highly respected work boasts a combined weight of more than 7 Kg. Their sheer size is a testament to the quantity of information contained inside. ... Each article ... is organized in a standardized way that helps make the information more digestible. ... The updated Manual has a place in all scientific libraries and its importance can only grow as we continue to explore and appreciate the vast prokaryotic diversity surrounding us." (Dawn Field, Microbiology Today, July, 2006)