@inproceedings{conan2001multiple,
title={Multiple covers and the integrality conjecture for rational curves in Calabi-Yau threefolds},
author={Conan Leung, Jim Bryan, and Sheldon Katz},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160831165811559924579},
booktitle={Journal of Alg Geom},
volume={10},
number={3},
pages={549-568},
year={2001},
}
Conan Leung, Jim Bryan, and Sheldon Katz. Multiple covers and the integrality conjecture for rational curves in Calabi-Yau threefolds. 2001. Vol. 10. In Journal of Alg Geom. pp.549-568. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160831165811559924579.