P. de S. Gonçalves, A. G. Rossetti, and J. R. de Paiva, “Repeatability coefficient and efficiency of micro tapping, test in seedlings of rubber tree”, PAB, vol. 17, no. 2, pp. 233–237, Apr. 2014, doi: 10.1590/S1678-3921.pab1982.v17.15618.