1. Cavicchioli, R. and Ostrowski, M., Encyclopedia of Life Sciences, 2003, pp. 1–8. www.els.net
2. Duda, V.I., Suzina, N.E., Polivtseva, V.N., and Boronin, A.M., Microbiology (Moscow), 2012, vol. 81, no. 4, pp. 379–390.
3. Workshop Size Limits of Very Small Microorganisms, Proceedings of a Workshop, Washington, DC: National Academy Press, 1999.
4. Schut, F., Prins, R.A., and Gottschal, J.C., Aquat. Microb. Ecol., 1997, vol. 12, no. 2, pp. 177–202.
5. Cavicchioli, R., Ostrowski, M., Fegatella, F., Goodchild, A., and Guixa-Boixereu, N., Microb. Ecol., 2003, vol. 45, no. 3, pp. 203–217.