1. XV. Vortex statics
2. Papers4, 141.
3. H. Lamb,Hydrodynamics(Dover Publications, Inc., New York, 1945), p. 317.
4. Einige Bemerkungen über Strömungen in rotierenden Flüssigkeiten
5. H. B. Squire,Surveys in mechanics, edited by G. K. Batchelor and R. M. Davies (Cambridge University Press, Cambridge, England, 1956), p. 139.