Gaia Collaboration, van Leeuwen, F., Vallenari, A., Jordi, C., Lindegren, L., Bastian, U., et al. (2017). Gaia Data Release 1 - Open cluster astrometry: performance, limitations, and future prospects. Astronomy & Astrophysics, 601: A19. doi:10.1051/0004-6361/201730552.