Fixed point theorems for better admissible multimaps on abstract convex spaces

In this paper, a better admissible class B⁺ is introduced and a new fixed point theorem for better admissible multimap is proved on abstract convex spaces. As a consequence, we deduce a new fixed point theorem on abstract convex ?-spaces. Our main results generalize some recent work due to Lassonde, Kakutani, Browder, and Park.