https://arxiv.org/abs/astro-ph/0601547
[astro-ph/0601547] Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging....
Abstract page for arXiv paper astro-ph/0601547: Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. IV: Measurement for Sculptor