↑ NASA/JPL/University of Texas Center for Space Research. "PIA12146: GRACE Global Gravity Animation". Photojournal. NASA Jet Propulsion Laboratory. Dicapai pada 30 December 2013.
↑ Hofmann-Wellenhof, B.; Moritz, H. (2006). Physical Geodesy (ed. 2nd). Springer. ISBN978-3-211-33544-4. § 2.1: "The total force acting on a body at rest on the earth’s surface is the resultant of gravitational force and the centrifugal force of the earth’s rotation and is called gravity."CS1 maint: postscript (link)
