Gross heating value of various shade-trees wood in coffee plantation in Costa Rica and its relation with extractives and specific gravity: : Gross heating value of various shade-trees wood in coffee plantation. (2018). Pelita Perkebunan (a Coffee and Cocoa Research Journal), 34(3), 183-190. https://doi.org/10.22302/iccri.jur.pelitaperkebunan.v34i3.311