The IACOB project - IX. Building a modern empirical database of Galactic O9 – B9 supergiants: Sample selection, description, and completenessA. de Burgos, S. Simón-Díaz, M. A. Urbaneja and I. NegueruelaA&A, 674 (2023) A212DOI: https://doi.org/10.1051/0004-6361/202346179
