References
==========

.. [FariasLiPeng22]
    Farias, Vivek, Andrew Li, and Tianyi Peng. 
    "Learning treatment effects in panels with general intervention patterns." Advances in Neural Information Processing Systems 34 (2021): 14001-14013.

.. [Arkhangelsky21]
    Arkhangelsky, Dmitry, Susan Athey, David A. Hirshberg, Guido W. Imbens, and Stefan Wager. 
    "Synthetic difference-in-differences." American Economic Review 111, no. 12 (2021): 4088-4118.

.. [Athey21]
    Athey, Susan, Mohsen Bayati, Nikolay Doudchenko, Guido Imbens, and Khashayar Khosravi. 
    "Matrix completion methods for causal panel data models." Journal of the American Statistical Association 116, no. 536 (2021): 1716-1730.