ETOPO2v2 (2006) 2-minute Gridded Global Data. U. S. Department of Commerce, National Oceanic and Atmospheric Administration, National Geophysical Data Center. http://www.ngdc.noaa.gov/mgg/fliers/06mgg01.html
Grafarend E. W., Voosoghi B. (2003) Intrinsic deformation analysis of the Earth's surface based on displacement fields derived from the space geodetic measurements. Case studies: present-day deformation patterns of Europe and of the Mediterranean area (ITRF data sets). Journal of Geodesy, Vol. 77, No. 5-6, pp. 303-326.
Holmes S. A., Featherstone W. E. (2002) A unified approach to the Clenshaw summation and the recursive computation of very high degree and order normalized associated Legendre functions. Journal of Geodesy, Vol. 76, No. 5, pp. 279-299.10.1007/s00190-002-0216-2
Ilk KH (1983) Ein Beitrag zur Dynamik ausgedehnter Körper - Gravitationswechselwirkung. Deutsche Geodätische Kommission, Reihe C, Heft Nr. 288, München.
Pavlis NK, Holmes SA, Kenyon SC, Factor JK (2008) An Earth Gravitational Model to Degree 2160: EGM2008, presented at the 2008 General Assembly of the European Geosciences Union, Vienna, Austria, April 13-18
Petrovskaya M. S., Vershkov A. N. (2006) Non-singular expressions of the gravity gradients in the local north-oriented and orbital reference frames. Journal of Geodesy, Vol. 80, No. 3, pp. 117-127.10.1007/s00190-006-0031-2
Petrovskaya M. S., Vershkov A. N. (2008) Development of the local north-oriented second order derivatives of the Earth potential in orthogonal series of modified spherical harmonics. Journal of Geodesy, Vol. 82, No. 12, pp. 929-944, DOI: 10.1007/s00190-008-0223-z.10.1007/s00190-008-0223-z