- Catalogue of Variable Stars in Globular Clusters - A catalogue of variable stars in globular clusters, featuring, for each cluster, single variables listed with pulsational parameters (period).
- Databases of Padova Astronomy Department - Databases maintained by the Padova Astronomy Department (Italy) with a lot of information for each galactic cluster. Three different databases are available: "Ground-based Data", "HST Snapshot" and "HST Deep".
- Globular Star Clusters - Information from SEDS on globular clusters.
