CDS, Strasbourg
Aladin previewer
WEBDA (Open Cluster Catalog)
arXiv e-Print archive
Staralt (Calculate visibility of objects)
The STScI Digitized Sky Survey
Newsletter of the IAU Working Group on Ap and Related Stars
ADPS - The Asiago Database on Photometric Systems

Asiago Observatory
Calar Alto Observatory
Complejo Astronomico el Leoncito (CASLEO, Argentina)
ENO - European Northern Observatory
ESO - LaSilla Observatory
Observatorio de Sierra Nevada