/. A. Smirl, G. C. Valley, R. A. Mullen, K. Bohnert, C. D. Mire et al., Picosecond photorefractive effect in BaTiO_3, Optics Letters, vol.12, issue.7, p.501, 1987.
DOI : 10.1364/OL.12.000501

/. A. Brun, G. L. Saux, G. Roger, F. Salin, and C. Baltimore, Photorefractive BSO response under femtosecond illumination, 1987.