@inbook{Hydrozoa:SourceID:164433, author = {Johansen, A. C. and Levinsen, J. C. L.}, journal = {Det Kongelige Danske Videnskabernes Selskabs Skrifter}, issue = {12}, pages = {265-297}, title = {Indledning. Coelenterater, Echinodermer, Chaetognater, Annelider, Pteropoder, Appendicularier, etc. In: De danske farvandes Plankton i Aarene 1898-1901}, url = {https://www.biodiversitylibrary.org/page/34684800}, volume = {6}, year = {1904} }