Moraes, Larissa Alexandra Cardoso, et al. “Relationship Between Stem Flexibility of Rubber Tree and Boron Deficiency”. Pesquisa Agropecuaria Brasileira, vol. 37, no. 10, Oct. 2002, pp. 1431-6, doi:10.1590/S1678-3921.pab2002.v37.6487.