Threshold behavior of semi-linear photorefractive oscillatorP. Mathey, M. Grapinet, H. R. Jauslin, B. Sturman, D. Rytz and S. OdoulovEur. Phys. J. D, 39 3 (2006) 445-451DOI: https://doi.org/10.1140/epjd/e2006-00127-x