1. On matroids, groups and exchange languages;Bjorner,1983
2. An abstract duality;Bland;IBM Research Report RC 12088,1986
3. A Unified Interpretation of Several Combinatorial Dualities;Bland;IBM Research Report RC 12527,1987
4. A Unifying Interpretation of Several Ccombinatorial Dualities;Dietrich,1986
5. A Circuit Set Characterization of Antimatroids;Dietrich;IBM Research Report RC 11981,1986