@article{JMLR:v27:24-0515,
  author  = {Zijian Guo and Mengchu Zheng and Peter B{{\"u}}hlmann},
  title   = {Robustness Against Weak or Invalid Instruments: Exploring Nonlinear Treatment Models with Machine Learning},
  journal = {Journal of Machine Learning Research},
  year    = {2026},
  volume  = {27},
  number  = {198},
  pages   = {1--67},
  url     = {http://jmlr.org/papers/v27/24-0515.html}
}