Walter S. Judd and Richard G. Olmstead (2004). "A survey of tricolpate (eudicot) phylogenetic relationships". American Journal of Botany. 91: 1627–1644. doi:10.3732/ajb.91.10.1627. (full text)
Walter S. Judd and Richard G. Olmstead (2004). "A survey of tricolpate (eudicot) phylogenetic relationships". American Journal of Botany. 91: 1627–1644. doi:10.3732/ajb.91.10.1627. (full text)
Sanford, Malcolm T. "Producing Pollen". Diarkibkan daripada yang asal pada January 13, 2007. Dicapai pada 2015-07-15., University of Florida, Institute of Food and Agricultural Sciences; citing P. Witherell, "Other Products of the Hive," Chapter XVIII, The Hive and the Honey Bee, Dadant & Sons, Inc., Hamilton, IL, 1975
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Sanford, Malcolm T. "Producing Pollen". Diarkibkan daripada yang asal pada January 13, 2007. Dicapai pada 2015-07-15., University of Florida, Institute of Food and Agricultural Sciences; citing P. Witherell, "Other Products of the Hive," Chapter XVIII, The Hive and the Honey Bee, Dadant & Sons, Inc., Hamilton, IL, 1975