  Time--dependent integrals of motion which are linear forms in position and
momentum are discussed for Husimi parametric forced oscillator. Generalization
of these integrals of motion for q--oscillator is presented. Squeezing and
quadrature correlation phenomena are discussed on the base of Schr\"odinger
uncertainty relation. The properties of the generalized correlated states,
squeezed states, even and odd coherent states (the Schr\"odinger cat states)
are reviewed. The relation of the constructed nonclassical states to
representations of the symplectic symmetry group and finite symmetry groups is
discussed.
