Photoacoustic study of gas permeability and diffusion in soils R.T. Faria Jr., S. Tibana, L.H. Poley, M.S. Sthel, F.T. de Almeida and H. Vargas J. Phys. IV France, 125 (2005) 673-675 DOI: 10.1051/jp4:2005125154