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.
Tzong-Chen Wu, Chin-Chen Chang. Controlling Access in Tree Hierarchies. Inf. Sci., 78(1-2):69-76, 1994.