1. Essai de classification des combustibles fossiles solides;Alpern;Pub. Tech. Charbonnage,1979
2. Pour une classification synthétique universelle des combustibles solides;Alpern;Bull. Centres Rech. Explor.-Prod. Elf-Aquitaine,1981
3. Some reflections on coal petrology and coal classification (keynote address);Alpern,1987
4. Project of an International Scientific Classification of Solid Fossil Fuels;Alpern,1987
5. Charbon du Bassin de Morungava. Etude de six forages;Alpern,1985