Proper projective collineation in non-static spherically symmetric   space-times
  We investigate the proper projective collineation in non-static spherically symmetric space-times using direct integration and algebraic techniques. Studying projective collineation in the above space-times, it is shown that the space-times which admit proper projective collineations turn out to be very special classes of static spherically symmetric space-times. 
Ghulam Shabbir, Amjad Ali