Researchr is a web site for finding, collecting, sharing, and reviewing scientific publications, for researchers by researchers.
Sign up for an account to create a profile with publication list, tag and review your related work, and share bibliographies with your co-authors.
David C. Littman, Jeannine Pinto, Elliot Soloway. The Knowledge Required for Tutorial Planning: An Empirical Analysis. Interactive Learning Environments, 1(2):124-151, 1990. [doi]
Abstract is missing.