1. D. P. Shorthouse, "SimpleMappr, an online tool to produce publication-quality point maps." , (2010)
2. et al. "IUCN Red List categories and criteria: version 3.1, ed. 2." , (2012)
3. A. E. Radford, W. C. Dickison, J. R. Massey, et al. "Vascular Plant Systematics." , (1974)
4. B. Ellis, D. Daly, L. J. Hickey, et al. "Manual of Leaf Architecture." , (2009)
5. H. J. Beentje, "The Kew plant glossary: as illustrated dictionary of plant terms." , (2016)