The study of change in the location of the geomagnetic north pole for the epoch (1900-2005) by using spherical harmonic coefficient. DJHR [انترنت]. 19 أغسطس، 2022 [وثق 5 يوليو، 2025];1(31). موجود في: https://djhr.uodiyala.edu.iq/index.php/DJHR2022/article/view/1976