The supernova remnants G 67.7+1.8, G 31.5-0.6 and G 49.2-0.7F. Mavromatakis, J. Papamastorakis, J. Ventura, W. Becker, E. V. Paleologou and D. SchaudelA&A, 370 1 (2001) 265-272DOI: https://doi.org/10.1051/0004-6361:20010137