  We put forward and prove several existence and uniqueness results for $L^p\
(p>1)$ solutions of reflected BSDEs with continuous barriers and generators
satisfying a one-sided Osgood condition together with a general growth
condition in $y$ and a uniform continuity condition or a linear growth
condition in $z$. A necessary and sufficient condition with respect to the
growth of barrier is also explored to ensure the existence of a solution. And,
we show that the solutions may be approximated by the penalization method and
by some sequences of solutions of reflected BSDEs. Our results improve
considerably some known works.
