BioStor
 | A CATALOG OF THE TYPE SPECIMENS OF THE CETONIINAE COLEOPTERA SCARABAEIDAE DESCRIBED BY G J ARROW WITH A COMPLETE BIBLIOGRAPHY OF HIS ENTOMOLOGICAL WORKS M E Bacchus (1974) Bulletin of The British Museum (Natural History) Entomology 31: 23-44 |
 | The genera of Cinchonoideae (Rubiaceae) in the southeastern United States G K Rogers (1987) Journal of the Arnold Arboretum 68: 137-183 |
 | Subfamilial and Tribal Relationships in the Rubiaceae Based on rbcL Sequence Data Birgitta Bremer, Katarina Andreasen and Daniel Olsson (1995) Annals of the Missouri Botanical Garden 82: 383-397 |
 | Taxonomic Revision of Cruckshanksia and Oreopolus (Rubiaceae: Hedyotideae) Charlotte M Taylor (1996) Annals of the Missouri Botanical Garden 83: 461-479 |