  We report on the measurement of various flow harmonics, $v_n$, with
multi-particle cumulants, and present the results from a study of the
inter-correlation among different order symmetry planes $\Psi_n$ via
multi-particle mixed harmonic correlations. This provides comprehensive
experimental information on the fluctuating event-by-event shape of the initial
conditions, which is currently among the main sources of large theoretical
uncertainties in describing the evolution of the system created in heavy-ion
collisions.
