LibreOffice - Wikipedia
Getting Started with Impress
Intro to LibreOffice Impress
LibreOffice 6.0 Writer Guide - The Document Foundation Blog
openSUSE Software
LibreOffice Impress - Master Slides
Impress (01) – Introduction to Impress
Chapter 6, Getting Started with Impress
LibreOffice: Introduction to Impress
Chapter 1, Introducing Impress
Chapter 1, Introducing Impress