Max-Planck-Institut für extraterrestrische Physik, 85740 Garching, Germany
Astronomy and Astrophysics 349, 389-405 (1999).
The catalogue can be used for scientific purposes as long as the above publication is referenced.
We plan to include further identifications of X-ray sources into the identification catalogue. Please contact xray-info (at) mpe . mpg . de, if you are interested to contribute your identifcations to this catalogue.