1. LOCAL EXISTENCE AND BLOW UP OF SOLUTIONS TO A LOGARITHMIC NONLINEAR WAVE EQUATION WITH TIME-VARYING DELAY. Authors: ABDELBAKI CHOUCHA, DJAMEL OUCHENANE.2. EXPONENTIAL GROWTH OF SOLUTIONS WITH LP-NORM OF A NONLINEAR VISCOELASTIC WAVE EQUATION WITH STRONG DAMPING AND SOURCE AND DELAY TERMS. Authors: DJAMEL OUCHENANE, ABDELBAKI CHOUCHA.