Lawal, Lasisi Salami, and Chris Reginald Chatwin. “A REVIEW OF GLOBAL NAVIGATION SATELLITE AND AUGMENTATION SYSTEMS”. IJRDO - Journal of Electrical And Electronics Engineering (ISSN: 2456-6055) 5, no. 3 (March 7, 2019): 01-21. Accessed September 16, 2019. https://ijrdo.org/index.php/eee/article/view/2731.