1. Alford, R., Shivashankar, V., Kuter, U., Nau, D.S.: HTN problem spaces: structure, algorithms, termination. In: Proceedings of the 5th Annual Symposium on Combinatorial Search (SoCS), pp. 2–9. AAAI Press, Palo Alto (2012)
2. Alford, R., Shivashankar, V., Kuter, U., Nau, D.: On the feasibility of planning graph style heuristics for HTN planning. In: Proceedings of the 24th International Conference on Automated Planning and Scheduling (ICAPS), pp. 2–10. AAAI Press, Palo Alto (2014)
3. Alford, R., Bercher, P., Aha, D.: Tight bounds for HTN planning. In: Proceedings of the 25th International Conference on Automated Planning and Scheduling (ICAPS), pp. 7–15. AAAI Press, Palo Alto (2015)
4. Alford, R., Bercher, P., Aha, D.: Tight bounds for HTN planning with task insertion. In: Proceedings of the 25th International Joint Conference on AI (IJCAI), pp. 1502–1508. AAAI Press, Palo Alto (2015)
5. Behnke, G., Höller, D., Biundo, S.: On the complexity of HTN plan verification and its implications for plan recognition. In: Proceedings of the 25th International Conference on Automated Planning and Scheduling (ICAPS), pp. 25–33. AAAI Press, Palo Alto (2015)