K. Cartwright and F. B. Sherman, Jr., “Electrical Earth Resistivity Surveying in Landfill Investigations,” Engineering and Soils Engineering Symposium Proceedings 10th Annual Meeting, Moscow, 1972, pp. 77-92.
 D. L. Warner, “Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water,” Groundwater, Vol. 7, No. 1, 1969, pp. 9-16. doi:10.1111/j.1745-6584.1969.tb01262.x
 W. O. Winsauer, H. M. Shearin, P. H. Masson and M. Williams, “Resistivity of Brine Saturated Sands in relation to Pore Geometry,” American Association of Petroleum Geologists Bulletin, Vol. 36, No. 2, 1952, pp. 253- 277.
 A. N. Ugbaja and A. E. Edet, “Groundwater Pollution near Shallow Waste Dumps in Southern Calabar, South- -Eastern Nigeria,” Global Journal of Geological Sciences, Vol. 2, No. 2, 2004, pp. 199-206.
 A. E. Edet and C. S. Okereke, “Delineation of Shallow Groundwater Aquifers in the Coastal Plain Sand of Calabar Area Using Surface Resistivity and Hydro-Geologi- cal,” Journal of African Earth Sciences, Vol. 35, No. 3, 2002, pp. 433-441. doi:10.1016/S0899-5362(02)00148-3
 D. H. Griffiths and R. D. Barker, “Two Dimensional Resistivity Imaging and Modeling in Areas of Complex Geology,” Journal of Applied Geophysics, Vol. 29, No. 3-4, 1993, pp. 211-226. doi:10.1016/0926-9851(93)90005-J
 M. Zamxaka, G. Pironcheva and N. Muyima, “Microbiological and Physico-Chemical Assessment of the Quality of Domestic Water Sources in Selected Rural Communities of the Eastern Cape Province, South Africa,” Water South Africa, Vol. 30, No. 30, 2004, pp. 333-339.
 A. O. Akankpo, G. T. Akpabio and I. O. Akpabio, “Physicochemistry and Biological Properties of Groundwater samples from Boreholes Sited near Waste Dumps in Uyo, Soutwestern Nigeria,” Natural and Applied Sciences Journal, Vol. 10, No. 2, 2009, pp. 156-165.