1. Abbak RA, Erol B, Ustun A (2012) Comparison of the KTH and remove-compute-restore techniques to geoid modelling in a mountainous area. Comput Geosci 48:31–40
2. Abbak RA, Sjöberg LE, Ellmann A, Ustun A (2012) A precise gravimetric geoid model in a mountainous area with scarce gravity data: a case study in central Turkey. Stud Geophys Geod 56(4)
3. Abdalla A (2009) Determination of a gravimetric geoid model of Sudan using the KTH method. Master’s thesis. Royal Institute of Technology (KTH), Stockholm
4. Abdalla A (2013a) The Combined Modelling of the Regional Quasigeoid of New Zealand Using Gravity and GPS-levelling Data. Phd thesis. University of Otago, New Zealand
5. Abdalla A (2013b) Towards a precise gravimetric geoid model in the Saudi Arabia (SAGEO13). Geoid Chapter in: Quasi-geoid model for Saudi Arabia: application for levelling with GPS. Technical report, Project no. 09-spa873-02, supported financially by the National Plan for Science, Technology and Innovation (NPST) program, King Saud University