The reaction e+ e- -> e+ e- gamma* gamma* -> e+ e- hadrons is analysed for
quasi-real virtual photons using data collected by the L3 detector during the
LEP high energy runs at sqrt(s) = 183 and 189 GeV. Preliminary results on the
cross sections sigma(e+e- -> e+e- hadrons) and sigma(gamma gamma -> hadrons)
are given in the interval 5 GeV < W_{gamma gamma} < 145 GeV. The centre-of-mass
energy dependence of the two-photon cross section is well described by the
universal Regge parametrisation, but with a steeper rise with energy as
compared to hadron-hadron cross sections. The data are also compared to the
expectations of different theoretical models. To investigate diffractive
processes, the elastic gamma gamma -> rho0 rho0 process and the inclusive rho0
production gamma gamma -> rho0 X are studied in the W_{gamma gamma} > 3 GeV
region. In all channels a comparison is made with the Pythia and Phojet Monte
Carlo generators.Comment: Presented at the Central European Triangle Symposium on Particle
Physics, Zagreb, Croatia, June, 17-19, 199
