The extremely young open cluster NGC 6611: Compiled catalogue, absorption map and the HR diagramA. N. Belikov, N. V. Kharchenko, A. E. Piskunov and E. SchilbachAstron. Astrophys. Suppl. Ser., 134 3 (1999) 525-536DOI: https://doi.org/10.1051/aas:1999154