1. The plant list: http://www.theplantlist.org/tpl/record/gcc-132866
2. https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=412045
3. Tela-botanica: http://www.tela-botanica.org/apd-nn-102912-synthese
4. The plant list: http://www.theplantlist.org/tpl1.1/search?q=Chrysanthellum+americanum+
5. Integrated Taxonomic Information System (ITIS): https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_ value=780251#null