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.
James Anderson, Tom Head. The lattice of semiretracts of a free monoid. Int. J. Comput. Math., 43(3-4):127-131, 1992. [doi]