To cite the service as such, we suggest the following BibTeX entry:
@MISC{vo:ASTRON_VO_Reg, year=2008, title={The VO @ {ASTRON} Registry}, author={{ASTRON}}, url={https://vo.astron.nl/__system__/services/registry/info}, howpublished={{VO} resource provided by the The VO @ {ASTRON}} }