Real Academia Española. «polen». Diccionario de la lengua española (23.ª edición). Consultado el 18 de marzo de 2015.
sierraclub.org
Sam Schipani (29 de mayo de 2018). «How the Honeybee Buzz Hurts Wild Bees». Sierra (revista)(en inglés). Sierra Club. Consultado el 1 de abril de 2024. «the total number of managed honeybees worldwide has risen by 45 percent over the last half century […] “Honeybees are not going to go extinct,” says Scott Black, executive director of the Xerces Society. “We have more honeybee hives than we’ve ever had».
Andrew Van Dam (29 de marzo de 2024). «Wait, does America suddenly have a record number of bees?». Washington Post(en inglés). Consultado el 1 de abril de 2024. «America’s honeybee population has rocketed to an all-time high […] We’ve added almost a million bee colonies in the past five years. We now have 3.8 million, the census shows […] the honeybee has been the fastest-growing livestock segment in the country».
