Gomes, I.F. et al. 2014. Comparative sampling methods for foliar diagnose in perennial cotton in Paraíba State, Brazil. Pesquisa Agropecuaria Brasileira. 17, 4 (Apr. 2014), 607–615. DOI:https://doi.org/10.1590/S1678-3921.pab1982.v17.15765.