From Spring in Action, 6th Edition by Craig Walls
From Learn Linux in a Month of Lunches by Steven Ovadia
Linux software installation, removal, and updating is handled by package managers. A package manager is what operates between us, the users, and the distribution software repositories. It’s where you look for software to install. The package manager is also what keeps software up-to-date on your computer.
From Learn Cisco Network Administration in a Month of Lunches by Ben Piper
This article discusses Cisco routers and switches.