L. Rivera Brenes, J. A. Arroyo, and A. Acosta Matienzo, “Acceptability Trials On Buffel Grass (Cenchrus ciliaris) and Guinea Grass Hybrid (Pannicum maxinium), as Compared with Napier (Merker) Grass (Pennisetum purpureum)”, JAUPR, vol. 52, no. 2, pp. 77–84, Apr. 1968.