Ubuntu: Unleashed 2017 Edition
Ubuntu: The Complete Reference
Ubuntu Linux Toolbox: 1000+ Commands for Ubuntu and Debian Power Users
Ubuntu Unleashed 2008 Edition: Covering 8.04 and 8.10
Getting Started with Ubuntu 16.04
Beginning Ubuntu Linux, Fourth Edition
Instant Ubuntu: Your complete guide to making the switch to Ubuntu
How to Do Everything: Ubuntu
Ubuntu Linux secrets
Ubuntu server essentials: unleash the true potential of Ubuntu server in your production environment using this administration guide
Beginning Ubuntu Linux: [the complete introduction to Ubuntu ; fully revised and updated for 10.04]
Beginning Ubuntu Server Administration: From Novice to Professional
A Practical Guide to Ubuntu Linux
Ubuntu Kung Fu: Tips, Tricks, Hints, and Hacks
Getting Started with Ubuntu 10.10
Ubuntu Linux toolbox : 1000+ commands for Ubuntu and Debian power users
Linux Bible: Boot Up to Fedora, KNOPPIX, Debian, SUSE, Ubuntu , and 7 Other Distributions
Ubuntu Linux for Non-Geeks: A Pain-Free, Project-Based, Get-Things-Done Guidebook