1. The principal continuation and the killer heuristic;Akl,1977
2. Proof-number search;Allis;Artificial Intelligence,1994
3. Searching for solutions in games and artificial intelligence, Ph.D. Thesis;Allis,1994
4. How to mate: Applying proof-number search;Breuker,1994
5. Memory versus search in games, Ph.D. Thesis;Breuker,1998