  In this paper, we establish a common fixed point theorem for two pairs of
occasionally weakly compatible single and set-valued maps satisfying a strict
contractive condition in a metric space. Our result extends many results
existing in the literature as those of Aliouche and Popa [15-20]. Also we
establish another common fixed point theorem for four owc single and set-valued
maps of Gregu% \v{s} type which generalizes the results of Djoudi and Nisse,
Pathak, Cho, Kang and Madharia and we end our work by giving a third theorem
which extends the results given by Elamrani & Mehdaoui and Mbarki.
