Nguimbous-Kouoh, J. J., E. N. Bum, and S. Ngos. “GRAVITY FIELD: THEORETICAL AND EXPERIMENTAL CONTRIBUTION TO STUDY WEIGHING PENDULUM PERIOD”.
JOURNAL OF ADVANCES IN PHYSICS
, vol. 9, no. 3, July 2015, pp. 2440-5, doi:10.24297/jap.v9i3.1348.