A. V. de Carvalho, B. J. R. Alves, and V. M. Reis, “Response of African oil palm to nitrogen addition and its influence on the diazotrophic bacteria population”, PAB, vol. 41, no. 2, pp. 293–300, Feb. 2006, doi: 10.1590/S1678-3921.pab2006.v41.7136.