classical 2-absorbing secondary submodules

In this work, we introduce the concept of classical 2-absorbing secondary modules over a commutative ring as a generalization of secondary modules and investigate some basic properties of this class of modules. let r be a commutative ring with identity. we say that a non-zero submodule n of an r-module mis a classical 2-absorbing secondary submodule of m if whenever a; b ∈ r, k is a submodule of m and abn ⊆ k, then an ⊆ k or bn ⊆ k or ab ∈ √ annr(n). this can be regarded as a dual notion of the 2-absorbing primary submodule.