@article{MS2_1987__61_2_186104, author = {Svein Mossige}, title = {On extremal h-bases {A...}}, journal = {Mathematica Scandinavica}, pages = {5--16}, publisher = {mathdoc}, volume = {61}, number = {2}, year = {1987}, zbl = {0621.10039}, url = {http://geodesic.mathdoc.fr/item/MS2_1987__61_2_186104/} }