Suggested books for certification

Hi all I'm a professional backend developer and system administrator, more than 20 years in this roles. I'm already using Google Cloud (more or less 10 years) for my projects but I would like to obtain one or more certification (mostly the DevOps and Security). Since I haven't had the chance to use all Google Cloud features professionally, especially around security and DevOps, I’d like to pick up a book (or a couple) to study. What would yo