Gomes, I. F.; Beltrão, N. E. de M.; Freire, R. M. M.; Galvão, S. J. Comparative Sampling Methods for Foliar Diagnose in Perennial Cotton in Paraíba State, Brazil. PAB 2014, 17 (4), 607-615. https://doi.org/10.1590/S1678-3921.pab1982.v17.15765.