Jones GD, Jones SD (2001). «The uses of pollen and its implication for Entomology». Neotropical Entomology30 (3): 314-349. doi:10.1590/S1519-566X2001000300001.
Stroo, A. (2000). «Pollen morphological evolution in bat pollinated plants». Plant Systematics and Evolution222 (1–4): 225-242. doi:10.1007/BF00984104.