1. Abdulla, M., Hassan, M. Z. and Athar, M.: Trace element intake through food and water. Pp 305-311. In: Trace and Toxic Elements in Nutrition and Health. M. Abdulla, S. B. Vohra and M. Athar (Eds.). Wiley Eastern Ltd, New Delhi (1995).
2. Ahuja, A.K. Mineral Intake by Low Income Group Men and Women in Sewage and Tube Well Irrigated Areas Around Ludhiana City. M.Sc Thesis, Punjab Agricultural University, Ludhiana (1997).
3. Encyclopedia Britannica: The New Encyclopedia Britanica. Vols 3, 4, 10, 13 and 19. Encyclopedia Britannica Inc., Chhicago, Illinois (1980).
4. ICMR: Nutrient Requirements and Recommended Dietary Allowances for Indians. Indian Council of Medical Research, NIN, Hyderabad (2000).
5. Sharma, V.K. Effect of FYM, Town Refuse and Sewage Water on Heavy Metal Consumption and Yield of Fodders and Vegetables. M.Sc Thesis, Punjab Agricultural University, Ludhiana (1981).