Cooper, G. P. a. R. (1931). The Evergreen Forests of Liberia.: A report on investigation made in the west african republic of liberia by the yale university school of forestry in cooperation with the firestone plantations company. Yale University.

Cooper, G. Proctor and Recorc. The Evergreen Forests of Liberia.: A Report on Investigation Made in the West African Republic of Liberia by the Yale University School of Forestry in Cooperation with the Firestone Plantations Company. New Haven: Yale University, 1931.

Cooper, G. Proctor and Recorc. The Evergreen Forests of Liberia.: A Report on Investigation Made in the West African Republic of Liberia by the Yale University School of Forestry in Cooperation with the Firestone Plantations Company. Yale University, 1931.