@article{GDZPPN002360527,
title = {The sum of two plane convex C... sets is not always C...},
journal = {Mathematica Scandinavica},
volume = {67},
year = {1990},
pages = {216-224},
zbl = {0739.52003},
url = {http://dml.mathdoc.fr/item/GDZPPN002360527}
}
Boman, Jan. The sum of two plane convex C... sets is not always C.... Mathematica Scandinavica, Tome 67 (1990) pp. 216-224. http://gdmltest.u-ga.fr/item/GDZPPN002360527/