1. Donwelliacaulis chlouberii gen. et sp. nov. (Guaireaceae, Osmundales) one of the oldest Mesozoic plant megafossils known in North America;Ash;Palaeontographica Abt. B,1994
2. Stelar morphology and the primary vascular system of seed plants;Beck;Bot. Rev.,1983
3. Morphology of Vascular Plants;Bierhorst,1971
4. Tyloses and the maintenance of transpiration;Canny;Ann. Bot.,1997
5. Wood, bark, and stem anatomy of new world species of Gnetum;Carlquist;Bot. J Linn. Soc.,1996