Erratum to: On the Number of Invariants in the Strain Energy Density of an Anisotropic Nonlinear Elastic Material with Two Material Symmetry Directions
1.Department of Structural Engineering, S?o Carlos School of Engineering,University of S?o Paulo,S?o Carlos,Brazil;2.Programa de Pós-Gradua??o Interunidades em Bioengenharia – EESC/FMRP/IQSC,University of S?o Paulo,S?o Carlos,Brazil