1. Chapter 2 - Petrology;George,1991
2. Variations in chemistry of macerals as reflected by micro-scale analysis of a Spanish coal;Mastalerz;Geol Acta: Int Earth Sci J,2013
3. The new inertinite classification (ICCP System 1994);International Committee for Coal Organic Petrology;Fuel,2001
4. Classification of huminite—ICCP System 1994;Sýkorová;Int J Coal Geol,2005
5. Chapter 8 - The Nature of Coal Material;Crelling,1989