1. Ako, B. D., and Olorunfemi M. O. (1989), Geoelectric survey for groundwater in the Newer Basalts of Vom Plateau State, Nig. J. Min. Geol. 25, 247–450.
2. Ali, H. O., and Whiteley, R. J. (1981), Gravity exploration for groundwater in the Bara Basin, Sudan, Geoexpl. 19, 127–141.
3. Arafin, M. S. (1988), Geophysical Investigation of the hydrogeology of Perlis. Unpub. Ph.D. thesis. University of Science Malaysia.
4. Arafin, M. S., and Lee, C. Y. (1987), Application of resistivity and induced polarization methods in locating karstic aquifers in Perlis. In: Proc. Int. Conf. Groundwater Environ, Kuala Lumpur.
5. Ballukraya, P. N. (2001), Hydrogeophysical investiagtions in namagiripettai area, Namakkal District, Tamil Nadu. J. Geol. Soc. India. 58, 239–249.