Hedström, I., Denzel, A. and Owens, G. 2006. Orchid bees as bio-indicators for organic coffee farms in Costa Rica: Does farm size affect their abundance?. Revista de Biología Tropical. 54, 3 (Sep. 2006), 965–969. DOI:https://doi.org/10.15517/rbt.v54i3.14075.