Dagne, E., T. Bekele, D. Bisrat, M. Alemayehu, T. Worku, and J. P. Elokaokich. “Essential Oils of Resins from three<i> Pinus</i> Species Growing in Ethiopia and Uganda”. SINET: Ethiopian Journal of Science, vol. 22, no. 2, June 2004, pp. 253-7, doi:10.4314/sinet.v22i2.18146.