K. O. Uma, “An Appraisal of the Groundwater Resources of the Imo River Basin, South eastern Nigerian,” Journal of Mining and Geology, Vol. 25, No. 1&2, 1989, pp. 305-315. http://dx.doi.org/10.1007/s12594-012-0126-8
 A. C. Ekwe and A. I. Opara, “Aquifer Transmissivity from Surface Geoelectrical Data: A Case Study of Owerri and Environs, Southeastern Nigeria,” Journal of the Geological Society of India, Vol. 80, No. 1, 2012, pp. 355-378.
 A. I. Opara, N. N. Onu and D. U. Okereafor, “Geophysical Sounding for the Determination of Aquifer Hydraulic Characteristics from Dar-Zurrock Parameters: Case study of Ngor Okpala, Imo River Basin, Southeastern Nigeria,” Pacific Journal of Science and Technology, Vol. 13, No. 1, 2012, pp. 590-603.
 H. T. Nejad, M. Mumipour, R. Kaboli and H. Najib, “Vertical Electrical Sounding (VES) Resistivity Survey Technique to Explore Groundwater in the Arid Region, Southeastern Iran,” Journal of Applied Sciences, Vol. 11, 2011, pp. 3765-3774.
 A. C. Ekwe, I. N. Nnodu, K. I. Ugwumbah and O. S. Onwuka, “Estimation of Aquifer Hydraulic Characteristics of Low Permeability Formation from Geosounding Data: A Case Study of Oduma Town, Enugu State,” Online Journal of Earth Sciences, Vol. 4, 2010, pp. 19-26. http://dx.doi.org/10.3923/ojesci.2010.19.26
 R. K. Majumdar and D. Das, “Hydrological Characterization and Estimation of Aquifer Properties from Electrical Sounding Data in Sagar Island Region, South 24 Parganas, West Bengal, India,” Asian Journal of Earth Sciences, Vol. 4, 2011, pp. 60-74. http://dx.doi.org/10.3923/ajes.2011.60.74
 E. O. Joshua, O. O. Odeyemi and O. O. Fawehinmi, “Geoelectric Investigation of the Groundwater Potential of Moniya Area, Ibadan,” International Research Journal of Geology and Mining, Vol. 3, 2011, pp. 54-62.
 J. Danielson, T. Dahlin, R.Owen, P. Mangeya and E. Auken, “Geophysical and Hydrogeologic Investigation of Groundwater in the Karoo Stratigraphic Sequence of Sawmills in Northern Mata beleland, Zimbabwe: A Case History,” Hydeogeological Journal, Vol. 15, 2007, pp. 945-960. http://dx.doi.org/10.1007/s10040-007-0191-z
 A. S. Akinwumiju and O. O. I. Orimoogunje, “Determining the Occurrence of Freshwater in the Aquifers of the Deltaic Formation, Niger Delta Nigeria,” Journal of Environmental & Analytical Toxicology, Vol. 3, No. 1, 2013, pp. 1-6.
 J. C. Egbai, “Vertical Electrical Sounding for the Determination of Aquifer Transmissivity,” Australian Journal of Basic and Applied Sciences, Vol. 5, 2011, pp. 1209-1214.
 S. N. Rai, S. Thiagarajan, Y. Ratna, V. kumari, R. Anand and A. Manglik, “Delineation of Aquifers in Basaltic Hard Rock Terrain Using Vertical Electrical Soundings Data,” Journal of Earth System Science, Vol. 122, No. 1, 2013, pp. 29-41.
 S. A. Van-dycke and M. Aboagye, “Geoelectrical Investigation of Groundwater Resources and Aquifer Characteristics in Some Small Communities in the Gushiegu and Karaga Districts of Northern Ghana,” International Journal of Scientific & Technology Research, Vol. 2, No. 3, 2013, pp. 25-35.
 G. Onwuchuriba, “Hydrogeochemical Analysis of Groundwater Samples in Umuahia and Environs,” Unpublished Bachelor of Science Thesis, Federal University of Technology, Owerri, 2002, 114 p.
 S. Onyekuru, “Depositional Patterns of Upper Cretaceous Sediments in the Southeastern Part of Anambra Basin, Southeastern Nigeria,” Unpublished Ph.D. Thesis, Federal University of Technology, Owerri, 2010, 280 p.
 R. A. Reyment, “Aspects of the Geology of Nigeria,” Ibadan University Press, 1965, pp. 56-63.
 A. J. Whiteman, “Nigeria: Its Petroleum Geology, Resources and Potential,” Graham and Trottan, London, 1982, 394 p.
 I. Arua, “Paleoenvironment of Eocene Deposits in the Afikpo Syncline, Southern Nigeria,” Journal of African Earth Sciences, Vol. 5 No. 33, 1986, pp. 279-284. http://dx.doi.org/10.1016/0899-5362(86)90017-5
 K. O. Uma and B. C. E. Egboka, “Groundwater Potentials of Owerri and Its Environs,” Geology and Mineral Resources of Nigeria, Vol. 22, 1985, pp. 57-64.
 A. C. Onyeagocha, “Petrography and Depositional Environment of the Benin Formation Nigeria,” Journal of Mining and Geology, Vol. 17, No. 2, 1980, pp. 147-151.
 L. O. Asseez, “Review of the Stratigraphy, Sedimentation and Structure of the Niger Delta. In: C. A. Kogbe, Ed., Geology of Nigeria, Eliza Beth Publishing Co., Lagos, 1976, 120 p.
 A. A. Avbovbo, “Tertiary Lithostratigraphy of Niger Delta,” Bulletin of American Association of Petroleum Geologists, Vol. 6, 1978, pp. 295-306.
 P. D. C. Mbonu, J. O. Ebeniro, C. O. Ofoegbu and A. S. Ekine, “Geoelectric Sounding for the Determination of Aquifer Characteristics in Parts of the Umuahia Area of Nigeria,” Geophysics, Vol. 56, No. 2, 1991, pp. 284-291. http://dx.doi.org/10.1190/1.1443042
 M. U. Igbokwe, E. E. Okwueze and C. S. Okereke, “Delineation of Aquifer Zones from Geoelectric Soundings in Kwa Ibo River Water shed, Southeastern Nigeria,” Journal of Engineering and Applied Sciences, Vol. 1, No. 4, 2006, pp. 410-421.
 P. Vingoe, “Electrical Resistivity Surveying,” ABEM Geophysical Memorandum, Vol. 5, No. 72, 1972, pp. 1-3.
 A. A. R. Zohdy, “Application of Surface Geophysics (Electrical Methods to Groundwater Investtigations),” Techniques for Water Resources Investigations in the United States, Section D, Book 2, 1976, pp. 5-55.
 O. Koefoed, “Geosounding Principles 1. Resistivity Sounding Measurements,” Elsevier, Amsterdam, 1977, p. 277.
 J. E. Osemeikhian and M. B. Asokhia, “Applied Geophysics for Engineers and Geologists,” Mc-Graw Hill, 1982, p. 155.
 A. C. Ekwe, N. N. Onu and K. M. Onuoha, “Estimation of Aquifer Hydraulic Characteristics of Aquifer Hydraulic Characteristics from Electrical Sounding Data: A Case of Middle Imo River Basin Aquifers, South Eastern Nigeria,” Journal of Spatial Hydrology, Vol. 6, 2006, pp. 121-132.
 S. D. Schwarz, “Application of Geophysical Methods to Groundwater Exploration in the Tolt River Basin, Washington State,” Geotechnical and Environmental and Engineering Geophysical Society European Section, E.E.G.S., 1988, pp. 9-12.
 R. A. Van Overmeeren, “Aquifer Boundaries Explored by Geoelectrical Measurements in the Coastal Plain of Yemen: A Case of Equivalence,” Geophysics, Vol. 54, No. 1, 1989, pp. 38-48. http://dx.doi.org/10.1190/1.1442575