We report the differential cross-section for events with large
total transverse energies, based on 112 pb^-1 ppbar collisions at sqrt s = 1.8
TeV.  The ratio of number of 3-jet to 2-jet events as a function of total
transverse energy is also presented.  Obtained results are compared with the
QCD expectations.  The properties of high mass six-jet events have been
studied.  Observed distributions are compared with the predictions of HERWIG
parton shower QCD, NJETS matrix element QCD, and a phase-space model in which
events are uniformly distributed in the kinematic allowed region of phase
space.

     A strong signal for Double Parton Scattering (DP) is observed in the
process pbar p  -> gamma + 3jets + X, using data from the CDF experiment.  The
fundamental DP parameter sigma_eff obtained, sigma_eff = 14.5 +/- 1.7^1.7_ -2.3
mb, represents a significant improvement over previous measurements.