1. Nwobodo TN, Anikwe MAN, Chukwu KE. Assessment of Spatio-temporal variation of groundwater quality in Udi-Ezeagu watershed. Enugu Area Southeastern Nigeria. 2015;3(4):210–7.
2. Luczaj J, Masarik K. Groundwater quantity and quality issues in a water-rich region: examples from Wisconsin, USA. Resources. 2015;5(1):10–3390. https://doi.org/10.3390/resources4020323 .
3. Buvaneshwari S, Riotte J, Ruiz L, Sekhar M, Mohan Kumar MS, Sharma AK, et al. High spatial variability of nitrate in the hard rock aquifer of an irrigated catchment: Implications for water resource assessment and vulnerability. Geophysical Research Abstracts, EGU General Assembly, Conference Abstracts. 2016. http://meetingorganizer.copernicus.org/EGU2016/EGU2016-5430-4.pdf .
4. Suthar S, Bishnoi P, Singh S, Mutiyar PK, Nema AK, Patil NS. Nitrate contamination in groundwater of some rural areas of Rajasthan, India. J hazar. Mater. 2009;171(1):189–99.
5. Tizro AT, Voudouris K, Vahedi S. Spatial variation of groundwater quality parameters: a case study from a semiarid region of Iran. Int bull water Resour & Dev. 2014;1:3.