Abstract Algebra
《Abstract Algebra》 · 第 366 页 · Section 10.4「Tensor Products of Modules」，Definition
Let $R$ and $S$ be any rings with 1. An abelian group $M$ is called an $(S,R)$-bimodule if $M$ is a left $S$-module, a right $R$-module, and $s(mr)=(sm)r$ for all $s\in S$, $r\in R$ and $m\in M$.