Triad Constraints for Learning Causal Structure of
           Latent Variables
             1      1          2        1,3         2
      Ruichu Cai , Feng Xie , Clark Glymour , Zhifeng Hao         , Kun Zhang
   1
     School of Computer Science, Guangdong University of Technology, Guangzhou, China
       2
        Department of Philosophy, Carnegie Mellon University, Pittsburgh, USA
       3
        School of Mathematics and Big Data, Foshan University, Foshan, China
      cairuichu@gdut.edu. ...