It is available for download the book
a CC text that explains how to get the most out of the LibreOffice Writer word processor (with a few pages dedicated to Draw, Math and Chart).
This book is a translation of an earlier book in Spanish called “Domando al escritor” which has a long history, its first incarnation being a series of articles dating back to 2006.
This edition is centred in LibreOffice 6.1, presenting also some of the new features that version 6.2 will give us in early 2019.
More information in the project page.