We prove that for any compact orientable connected –manifold with torus boundary, a concatenation of it and the direct product of the circle and the Klein bottle with an open –disk removed admits a Lagrangian embedding into the standard symplectic –space. Moreover, the minimal Maslov number of the Lagrangian embedding is equal to .
"On Lagrangian embeddings of closed nonorientable $3$–manifolds." Algebr. Geom. Topol. 19 (4) 1619 - 1630, 2019. https://doi.org/10.2140/agt.2019.19.1619