de Araújo, E. Freitas; de Queiroz, L. Paganucci & Machado, M.A. (2003): What is Citrus? Taxonomic implications from a study of cp-DNA evolution in the tribe Citreae (Rutaceae subfamily Aurantioideae). Organisms Diversity & Evolution3(1): 55-62. doi:10.1078/1439-6092-00058 (HTML abstract)
Grant, Matthew; Blackmore, Stephen & Morton, Cynthia (2000): Pollen morphology of the subfamily Aurantioideae (Rutaceae). Grana39(1): 8-20. doi:10.1080/00173130150503768PDF fulltext