1. Bericht des Ausschusses fuer die Wasserversorgung Wiens, , , Oester. Ing. u. Arch. Verela, , 1895, , referred to by VEATCH in U. S. Geol. Surv. W.-S. and Irr. Paper 155, p. 34, 1906.
2. U. S. Geol. Surv. W.-S. Paper;Hoyt,1936
3. U. S. Geol. Surv. W.-S. Paper;Leggette,1942
4. Leggette, R. M., , , ibid., Fig. 8, p. 114 .
5. Boussinesq, J., , , J. math, pures et appliques, Sér, , (5) , v. 10, , pp. 11 et seq., 1904, .