Direct observation of betatron oscillations in a laser-plasma electron accelerator Y. Glinec, J. Faure, A. Lifschitz, J. M. Vieira, R A. Fonseca, L. O. Silva and V. Malka EPL, 81 6 (2008) 64001 Published online: 20 February 2008 DOI: 10.1209/0295-5075/81/64001