@inproceedings{sergei2003duality,
title={Duality and Fibrations on G_2 Manifolds},
author={Sergei Gukov, Shing-Tung Yau, and Eric Zaslow},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224203744084488080},
booktitle={Turkish Journal of Mathematics},
volume={27},
number={1},
pages={61-98},
year={2003},
}

Sergei Gukov, Shing-Tung Yau, and Eric Zaslow. Duality and Fibrations on G_2 Manifolds. 2003. Vol. 27. In Turkish Journal of Mathematics. pp.61-98. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224203744084488080.