Beer, J., Harvey, C. A., Ibrahim, M. A., Somarriba, E., Harmand, J. M., & Jiménez Otárola, F. (2003). Service functions of agroforestry systems.

Beer, John, Celia A. Harvey, Muhammad Akbar Ibrahim, Eduardo Somarriba, Jean Michel Harmand, a Francisco Jiménez Otárola. Service Functions of Agroforestry Systems. 2003.

Beer, John, et al. Service Functions of Agroforestry Systems. 2003.