  The purpose of this paper is to introduce Harvey-Lawson manifolds and review
the construction of certain mirror dual Calabi-Yau submanifolds inside a G_2
manifold. More specifically, given a Harvey-Lawson manifold HL, we explain how
to assign a pair of tangent bundle valued 2 and 3-forms to a G_2 manifold
(M,HL, \varphi, \Lambda), with the calibration 3-form \varphi and an oriented
2-plane field \Lambda. These forms can then be used to define different complex
and symplectic structures on certain 6-dimensional sub bundles of T(M). When
these bundles are integrated they give mirror CY manifolds (related thru HL
manifolds).
