1. Lamb H.: Hydrodynamics (3rd ed.). 1906, p. 538.
2. Craig T.: Am. J. Math.III (1880) 286.
3. Stekloff W.: Annales de la Faculté des Sciences de Toulouse, II. sér. 10 (1908), p. 320.
4. Minchin G. M.: Uniplanar kinematics of solids and fluids. Oxford, 1882, p. 244.