Dana Angluin James Aspnes Jiang Chen David Eisenstat Lev Reyzin Learning Acyclic Probabilistic Circuits Using Test Paths. 169-180 2008 COLT http://colt2008.cs.helsinki.fi/papers/71-Angluin.pdf conf/colt/2008 db/conf/colt/colt2008.html#AngluinACER08