Smith, D.G. 2001. Chapter 3. Cnidaria. (In). D.G. Smith. Pennak's Freshwater Invertebrates of the United States. John Wiley, New York.
Campbell, R.D. 2016. Chapter 4. Phylum Cnidaria. (In) J.H. Thorp and D.C. Rogers. Keys to Nearctic Fauna. Thorp and Covich's Freshwater Invertebrates, Vol. II (4th ed). Academic Press. London.