PZ-90 (short for Parametry Zemli 1990 goda, in Russian: Параметры Земли 1990 года) is a geodetic datum defined for use in the GLONASS system.[1][2]
^J. Sanz Subirana; J.M. Juan Zornoza; M. Hernández-Pajares. "Reference Frames in GNSS". ESA Navipedia. Technical University of Catalonia, Spain. Retrieved 1 February 2016.