The closed convex hull of the interpolating Blaschke products contains any bounded analytic function of sufficiently small norm.
@article{urn:eudml:doc:41297, title = {The closed convex hull of the interpolating Blaschke products.}, journal = {Publicacions Matem\`atiques}, volume = {41}, year = {1997}, pages = {659-669}, mrnumber = {MR1485510}, zbl = {0894.30021}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:41297} }
Oyma, Knut. The closed convex hull of the interpolating Blaschke products.. Publicacions Matemàtiques, Tome 41 (1997) pp. 659-669. http://gdmltest.u-ga.fr/item/urn:eudml:doc:41297/