  The purpose of this paper is to study Rota-Baxter operators for
BiHom-associative algebras. Moreover, we introduce and discuss the properties
of the notions of BiHom-(tri)dendriform algebra, BiHom-Zinbiel algebra and
BiHom-quadri-algebra. We construct the free Rota-Baxter BiHom-associative
algebra and present some observations about categories and functors related to
Rota-Baxter structures.
