Vittorio Castelli Daniel Oblinger Lawrence D. Bergman Augmentation-Based Learning combining observations and user edits for Programming-by-Demonstration. 575-591 2007 20 Knowl.-Based Syst. 6 http://dx.doi.org/10.1016/j.knosys.2007.04.007 db/journals/kbs/kbs20.html#CastelliOB07