According to our database1, Jonathan Bauer authored at least 3 papers in 1991.
Legend:Book In proceedings Article PhD thesis Other
Inheritance for ADTs (revised)
ANSI X2H2, July, 1991
Object ADTs (with improvements for Value ADTs)
ANSI X3H2, April, 1991
ADT-based Type System for SQL.
Proceedings of the Query Processing for Advanced Database Systems, 1991