Viera, C. J., Kopsell, E., Beer, J., Jiménez Otárola, F., & Lok, R. (1999). Forestry incentives to establish and manage timber trees in coffee fields.

Viera, Carlos J., Edgar Kopsell, John Beer, Francisco Jiménez Otárola, و Rosanna Lok. Forestry Incentives to Establish and Manage Timber Trees in Coffee Fields. 1999.

Viera, Carlos J., et al. Forestry Incentives to Establish and Manage Timber Trees in Coffee Fields. 1999.