Close On the Uncertainties in the Measurement of Absolute (True) TEC over Indian Equatorial and Low Latitude Sectors,
Rao Rama, P. V. S., K. Venkatesh, D. S. Prasad, K. Niranjan (2013),
Advances in Space Research, 51 p. 1238–1252,
10.1016/j.asr.2012.10.032.