Seminar on Triples and Categorical Homology Theory : ETH 1966/67

by Appelgate, H., Barr, M., Beck, J., Lawvere, F. W.
Published 1969

Reports of the Midwest Category Seminar IV

by Applegate, H., Barr, M., Day, E., Dubuc, E.
Published 1970

Exact Categories and Categories of Sheaves

by Barr, M., Grillet, P. A., Osdol, D. H. van
Published 1971

*- Autonomous Categories

by Barr, M.
Published 1979