@article{StephanSpiegelberg2010, author = {R{\"u}diger Stephan and Ingo Spiegelberg}, title = {On cardinality constrained polymatroids}, journal = {Electronic Notes in Discrete Mathematics}, volume = {36}, pages = {1017 -- 1024}, doi = {DOI: 10.1016/j.endm.2010.05.129}, url = {http://www.sciencedirect.com/science/article/B75GV-50JJF7F-4K/2/2761e6edfcb262af0ba4856767d82a42}, year = {2010}, }