1. Albertella, A., F. Sacerdote, and F. Sansò, Geodetic calculus with block-averages observations on the sphere, Surv. Geophys., 14(4–5), 395–402, 1993.
2. Bjerhammar, A., Theory of Errors and Generalized Matrix Inverses, 420 pp., Elsevier Scientific Publ Co., Amsterdam, 1973.
3. Bjerhammar, A., A stochastic approach to the mixed boundary value problem in physical geodesy, in Geodesy in Transition, A volume dedicated to Helmut Moritz on the occasion of his 50th birthday, edited by Schwarz, K. P. and Lachapelle, G., Division of Surveying engineering, p. 25–42, The University of Calgary, Canada, 1983.
4. Eshagh, M., On Satellite Gravity Gradiometry, 222 pp., Doctoral thesis in Geodesy, Royal Institute of Technology, Stockholm, Sweden, 2009.
5. Eshagh, M. and L. E. Sjöberg, The modified best quadratic unbiased non-negative estimator (MBQUNE) of variance components, Stud. Geophys. Geod., 52, 305–320, 2008.