To cite the service as such, we suggest the following BibTeX entry:
@MISC{vo:UCL_Astro_Reg, year=2008, title={{UCL} {DaCHS} server Registry}, author={Patrick Guio}, url={http://astroweb.projects.phys.ucl.ac.uk:8000/__system__/services/registry/info}, howpublished={{VO} resource provided by the {UCL} {DaCHS} server} }