1. Abramowitz, M., Stegun, I.A.: Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, 9th printing. New York, Dover, 1972
2. Ackermmann, H.A., Dix, C.H.: The first vertical derivative of gravity. Geophysics, 20, 148–154, 1955
3. Arfken, G.: Mathematical Methods for Physicists, 5th ed. Academic Press, New York,1128pp., 2001
4. Byerly, W.E.: An Elementary Treatise on Fourier’s Series, and Spherical, Cylindrical, and Ellipsoidal Harmonics, with Applications to Problems in Mathematical Physics. New York, Dover, 287pp., 1959, 1993, 2003
5. Carnahan, B., Luther, H.A., Wilkes, J.O.: Applied Numerical methods. New York, Wiley, 1969