van Leeuwen, F., Vallenari, A., Jordi, C., Lindegren, L., Bastian, U., Prusti, T., et al. (2017). Gaia Data Release 1. Open cluster astrometry: performance, limitations, and future prospects. Astronomy and Astrophysics, A19, pp. 1-65. doi:10.1051/0004-6361/201730552.