1. Plant uptake and DTPA-extractability of Cd, Cu, Ni and Zn in a Norwegian alum shale soil as affected by previous addition of dairy and pig manures and peat
2. Dependence of DTPA‐extractable Zn, Fe, Mn, and Cu availability on organic carbon presence in arid and semiarid soils of Punjab
3. Bhogal, N. S., Sakal, R., Singh, A. P. & Sinha, R. B. (1993). Micronutrient status in Aquic Ustifluvents and Udifluvents as related to certain soil properties. Journal of the Indian Society of Soil Science, 41(1), 75-78.
4. Bhupender, S., (2014). Appraisal of fertility indices of the soils of Degana tehsil, Nagaur district (Rajasthan). Asian Journal of Soil Science, 9(1), 100-102.
5. Blackmore S., Godwin R.J., Taylor J.C., Cosser, N.D., Wood, G.A., Earl, R.&Knight, S. (1998). Understanding variability in four fields in the United Kingdom. In: Robert PC, Rust RH, Larson W (eds) Proceedings of the 4th international conference on precision agriculture. ASA, CSSA, SSSA, Madison, WI, pp 3 – 18.