Problem Solvers that Learn. - Brent J. Krawchuk; Ian H. Witten (EWSL, 1988)

On Asking the Right Questions. - Brent J. Krawchuk; Ian H. Witten (ML, 1988)

Explanation-based learning: its role in problem solving. - Brent J. Krawchuk; Ian H. Witten (J. Exp. Theor. Artif. Intell., 1989)