Beam divergence of high-order harmonics generated in the few-optical cycle regime C. Altucci, R. Bruzzese, C. de Lisio, V. Tosa, P. Barbiero, L. Poletto, G. Tondello, P. Villoresi, M. Nisoli, S. Stagira et al. (3 de plus) J. Phys. IV France, 11 PR2 (2001) Pr2-351-Pr2-354 DOI: 10.1051/jp4:2001268