1. Abraham, A. 2021. Evaluation of multi trait PGPR Bacillus safensis for plant growth promotion and zinc solubilization in turmeric. MSc thesis, Kochi: Kerala University of Fisheries and Ocean Studies.
2. Alloway, B.J. 2009. Soil factors associated with zinc deficiency in crops and humans. Environmental Geochemistry and Health 31: 537–548.
3. Anandaraj, M., and Y.R. Sarma. 1994. Effect of vesicular arbuscular mycorrhiza on rooting of black pepper (Piper nigrum L.). Journal of Spices and Aromatic Crops 3: 39–42.
4. ———. 1995. Diseases of black pepper (Piper nigrum L.) and their management. Journal of Spices and Aromatic Crops 4: 17–23.
5. ———. 1997. Mature coconut water for mass culture of biocontrol agents. Journal of Plantation Crops 25: 112–114.