Last modified date: <%+ tp.file.last_modified_date() %> Tags: #todo/untagged Refs: D.S. Metzler, Topological and smooth stacks, math.DG/0306176, 2003 B. Noohi, Foundations of topological stacks, math.AG/0503247, 2005. B. Noohi, Homotopy types of topological stacks, arXiv:0808.3799, 2008 Links: #todo/create-links topological stack Motivations Homotopy theory Topological groupoid