  This paper investigates some univariate and bivariate constrained
interpolation problems using rational quartic fractal interpolation functions,
which has been submitted long back in a reputed journal and revised as per the
journal requirement. This research is extension of the work [S. K. Katiyar and
A. K. B. Chand, Shape Preserving Rational Quartic Fractal Functions, Fractal,
in Press].
