I thought this revised edition printed in 1988 would contain information on PKD books printed between 1981 (original bibliography) and 1988 but I was wrong. The only changes between the first and revised editions are 3 tiny corrections that you would have difficulty finding. Each page looks identical. This revised edition is a digital reprint with bad quality scans of his books and in a tacky plastic cover. In no way is the quality comparable to the 1981 edition. Not worth it for the price.