H. Morais, C. J. Marur, P. H. Caramori, A. M. de A. Ribeiro, and J. C. Gomes, “Physiological characteristics and growth of coffee plants grown under shade of pigeonpea and unshaded”, PAB, vol. 38, no. 10, pp. 1131–1137, Oct. 2003, doi: 10.1590/S1678-3921.pab2003.v38.6682.