Campos, Tarcísio Gomes da Silva, and Francisco Assis de Oliveira. “Effects of Urea-N Levels on Yield of Irrigated Upland Cotton, Cv. Cnpa Precoce 1”. Pesquisa Agropecuaria Brasileira, vol. 26, no. 9, Sept. 1991, pp. 1381-5, doi:10.1590/S1678-3921.pab1991.v26.3477.