1. Cenospheres;Pedlow,1973
2. Cenospheres from Dry Fly Ash;Jan de Zeeuw,1976
3. Micro-spheres: Selected Problems;Hycnar,1977
4. Micro-spheres — their Occurrence, Properties and Apllication;Hycnar;Energetyka,1979
5. Micro-spheres — New Heat Insulating Material;Hycnar;Gospodarka Paliwami i Energia,1982