Influence of growth rings position of wood on the determination of its shear strength parallel to grain oleh E.F.C. Rodrigues, V.A. De Araujo, R.S. Cavalheiro, L.J. Marini, J.P.B. Almeida, A.R.G. Azevedo, L.B. Oliveira, F.A.R. Lahr, H.F. dos Santos, A.L. Christoforo