Havlin, J. L., Beaton, J. D., Tislade, S. L., & Nelson, W. L. (2005). Soil Fertility and Fertilizers: An introduction to nutrient management (7th edición.). Pearson Prentice Hall.

Havlin, John L., James D. Beaton, Samuel L. Tislade, and Werner L. Nelson. Soil Fertility and Fertilizers: An Introduction to Nutrient Management. 7th edición. Upper Saddle River, New Jersey: Pearson Prentice Hall, 2005.

Havlin, John L., et al. Soil Fertility and Fertilizers: An Introduction to Nutrient Management. 7th edición. Pearson Prentice Hall, 2005.