Al-Akhaly I. The International Geomagnetic Reference Field in Yemen at the Beginning of 2020 and the Secular Variations during the Period from 1900 to 2020. JOPAS [Internet]. 2021 May 12 [cited 2026 Nov. 4];20(1):153-66. Available from: https://www.sebhau.edu.ly/journal/jopas/article/view/1181