1. Flowering Plants of The World;Heywood,1978
2. The Families and Genera of Vascular Plants. Volume II: Flowering Plants, Cabombaceae;Williamson,1993
3. The Families and Genera of Vascular Plants. Volume II: Flowering Plants, Nelumbonaceae;Williamson,1993
4. The Families and Genera of Vascular Plants. Volume II: Flowering Plants, Nymphaeaceae;Schneider,1993
5. The chemical and anatomical compositions of coal precursors;Ryan,1985