@article{Kessler_2018, title={Review of Geodesy: Introduction to Geodetic Datum and Geodetic Systems}, url={https://cartographicperspectives.org/index.php/journal/article/view/1508}, DOI={10.14714/CP91.1508}, number={91}, journal={Cartographic Perspectives}, author={Kessler, Fritz}, year={2018}, month={Nov.}, pages={168–170} }