Properties of dust in the detached shells around U Antilae, DR Serpentis, and V644 Scorpii M. Maercker, T. Khouri, E. De Beck, M. Brunner, M. Mecina and O. Jaldehag A&A, 620 (2018) A106 Published online: 04 December 2018 DOI: 10.1051/0004-6361/201833665