Photoacoustic investigation of copaiba oil J. G. Santos, L. B. Silveira, L. Olenka, A. C. Oliveira, A. F.R. Rodriguez, V. Garg, A. C. Bento, R. G. Oliveira and P. C. Morais Eur. Phys. J. Special Topics, 153 (2008) 523-526 Published online: 12 March 2008 DOI: 10.1140/epjst/e2008-00499-y