@inproceedings{sgem2019s09038,
  title = {NORMAL HEIGHT AND GEOPOTENTIAL NUMBER DIFFERENCES DETERMINATION FOR THE TERRITORY OF BULGARIA WITH USE OF DATA FROM GLOBAL GRAVITY FIELD MODELS},
  author = {Tatyana Lambeva},
  booktitle = {SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 19th International Multidisciplinary Scientific GeoConference SGEM2019, Informatics, Geoinformatics and Remote Sensing},
  year = {2019},
  pages = {309-318},
  publisher = {STEF92 Technology},
  doi = {10.5593/sgem2019/2.2/s09.038}
}