Epistasis has been a well-known hard problem in optimization solved by evolution, especially by cooperative coevolution. Standard cooperative coevolution usually gets worse performance than standard evolution for optimization problems with epistasis. In this work, we propose a much improved version of cooperative coevolutionary model by using reference sharing collaboration. Pareto dominance is used for measuring the performance of individuals in our algorithm. We evaluate and compare our method with standard evolution and cooperative coevolution on a suite of test problems with and without epistasis interaction. Our experimental results show that the proposed algorithm outperforms the compared methods in most of the cases, and especially, it is superior to the standard evolution to handle epistasis.