The study of change in the location of the geomagnetic north pole for the epoch (1900-2005) by using spherical harmonic coefficient. مجلة ديالى للبحوث الانسانية, Iraq, v. 1, n. 31, 2022. DOI: 10.57592/djhr.v1i31.1976. Disponível em: https://djhr.uodiyala.edu.iq/index.php/DJHR2022/article/view/1976. Acesso em: 5 2025.