@article{Zhao:2020Wt, author = "Zhao, Yidi and Christ, Norman H. and Feng, Xu and Jin, Luchang and Tu, Cheng", title = "{Calculating the two-photon contribution to $\pi^0 \rightarrow e^+ e^-$ decay amplitude}", doi = "10.22323/1.363.0097", journal = "PoS", year = 2020, volume = "LATTICE2019", pages = "097" }