@article{AM2_1981__22_136871,
     author = {Charles B. Dunham},
     title = {Rational approximation on subsets, {II.}},
     journal = {Aequationes mathematicae},
     pages = {165--172},
     year = {1981},
     volume = {22},
     zbl = {0492.41039},
     url = {http://geodesic.mathdoc.fr/item/AM2_1981__22_136871/}
}