Checklist of Ferns and Lycophytes of the World
URL: http://worldplants.webarchiv.kit.edu/ferns/index.phpBy Michael Hassler and Bernd Schmitt, Version 5.12. Covering 14,327 taxa, 12,634 species and 46,380 synonyms. Including 4,259 pictures of 1,282 species. With special support by Ralf Knapp (Taiwan). In cooperation with Botanical Garden of the Karlsruhe Institute of Technology.