Mussak, Michael F., and Jan G. Laarman. (1989) 1989. “Farmers’ Production of Timber Trees in the Cacao-Coffee Region of Coastal Ecuador”. Agroforestry Systems 9 (2): 155-70. doi:10.1007/BF00168260.
shade trees
Singh, K. A., R. N. Rai, Patiram Bhutia, and D. T. Bhutia. (1989) 1989. “Large Cardamom (Amomum Subulatum Roxb.) Plantation - An Age Old Agroforestry System in Eastern Himalayas”. Agroforestry Systems 9 (3): 241-57. doi:10.1007/BF00141087.
Teketay, D., and A. Tegineh. (1991) 1991. “Traditional Tree Crop Based Agroforestry in Coffee Producing Areas of Harerge, Eastern Ethiopia”. Agroforestry Systems 16 (3): 257-67. doi:10.1007/BF00119322.