This service has an associated publication. If you use its data, it may be appropriate to reference Apparent Places of Fundamental Stars, Karlsruhe: G. Braun, ISSN 0174-254 X either in addition to or instead of the service reference.
To cite the service as such, we suggest the following BibTeX entry:
@MISC{vo:apfs_catquery,
year=2007,
title={{APFS} Ephemeris for FK6 Stars},
author={{GAVO} Data Centre},
url={http://dc.g-vo.org/apfs/res/apfs_new/catquery/info},
howpublished={{VO} resource provided by the {GAVO} Data Center}
}