The GSC-II-based survey of ancient cool white dwarfs - I. The sample of spectroscopically confirmed white dwarfsD. Carollo, B. Bucciarelli, S. T. Hodgkin, M. G. Lattanzi, B. McLean, R. Morbidelli, R. L. Smart, A. Spagna and L. TerranegraA&A, 448 2 (2006) 579-588DOI: https://doi.org/10.1051/0004-6361:20054113
