Neutron quasi-elastic scattering study of translational motions in the smectic h, c and a phases of tbba A.J. Dianoux, F. Volino, A. Heidemann et H. HervetJ. Physique Lett., 36 11 (1975) 275-277DOI: https://doi.org/10.1051/jphyslet:019750036011027500