Frissel, M. J., & Van Veen, J. A. (1981). Simulation of nitrogen behaviour of soil-plant systems: Paper of a workshop models for the behaviour of nitrogen in soil and uptake by plant..., Wageningen, the Netherlands, January 28 - February 1, 1980. Wageningen: Centre for Agricultural Publishing and Documentation.

Frissel, M. J., and J. A. Van Veen. Simulation of Nitrogen Behaviour of Soil-plant Systems: Paper of a Workshop Models for the Behaviour of Nitrogen in Soil and Uptake By Plant..., Wageningen, the Netherlands, January 28 - February 1, 1980. Wageningen: Centre for Agricultural Publishing and Documentation, 1981.

Frissel, M. J., and J. A. Van Veen. Simulation of Nitrogen Behaviour of Soil-plant Systems: Paper of a Workshop Models for the Behaviour of Nitrogen in Soil and Uptake By Plant..., Wageningen, the Netherlands, January 28 - February 1, 1980. Wageningen: Centre for Agricultural Publishing and Documentation, 1981.