Hermsen, Elizabeth J. et al.: Azolla Sporophytes and Spores from the Late Cretaceous and Paleocene of Patagonia, Argentina. International Journal of Plant Sciences, 19.07.2019, 180. vsk, nro 7, s. 737–754. The University of Chicago Press. doi:10.1086/704377. Artikkelin verkkoversio. Viitattu 12.2.2021. (englanniksi)
”Floating aquatic macrophytes – Azolla”, Use Of Algae And Aquatic Macrophytes As Feed In Small-Scale Aquaculture. A Review: FAO Fisheries And Aquaculture Technical Paper No. 531. Rooma: Food and Agriculture Organization of the United Nations, 2010. ISBN 978-92-5-106420-7. Luku PDF-muodossa (viitattu 12.2.2021). (englanniksi)
Hermsen, Elizabeth J. et al.: Azolla Sporophytes and Spores from the Late Cretaceous and Paleocene of Patagonia, Argentina. International Journal of Plant Sciences, 19.07.2019, 180. vsk, nro 7, s. 737–754. The University of Chicago Press. doi:10.1086/704377. Artikkelin verkkoversio. Viitattu 12.2.2021. (englanniksi)