1. Intergovernmental Platform on Biodiversity and Ecosystem Services, The Assessment Report of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services on Pollinators, Pollination and Food Production (Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, 2016).
2. D. Bolton, Independent Digital News & Media, 2016; www.independent.co.uk/environment/bee-decline-dying-out-honeybees-uk-food-production-extinction-a6939266.html.
3. Impact of the introduced honeybees (Apis mellifera, Apidae) on Teide National Park (Tenerife, Canary Islands)
4. The Nature Conservancy, Bees and Agriculture (The Nature Conservancy, 2017); www.nature.org/ourinitiatives/regions/northamerica/unitedstates/indiana/journeywithnature/bees-agriculture.xml.
5. Greenpeace, SOS-bees (Greenpeace, 2014); http://sosbees.org/situation.