Topological Defects - This is an introductory set of lecture notes on topological defects, given to an audience with interests ranging from astronomy to particle physics.
Topological Defects - A site with links to papers and workshops on topological defects in cosmology
Topological Defects in Cosmology - A review by Ajit M. Srivastava of various topological defects in particle theoryu models of the early universe (in PDF format).