Star Clusters

Lacaille's Catalog of Nebulae of the Southern Sky - A discussion of Lacaille's catalog, which is mainly of historical interest. Includes the catalog itself.
www.seds.org/messier/xtra/history/lacaille.html

Stellar Clusters - Lecture notes by Professor Barbara Ryden.
www-astronomy.mps.ohio-state.edu/~ryden/ast162_4/notes17.html