Kaleidoscope: A Constraint Imperative Programming Language. - Gus Lopez; Bjørn N. Freeman-Benson; Alan Borning (NATO ASI CP, 1993)

Constraints and Object Identity. - Gus Lopez; Bjørn N. Freeman-Benson; Alan Borning (ECOOP, 1994)

Implementing Constraint Imperative Programming Languages: The Kaleidospace'93 Virtual Machine. - Gus Lopez; Bjørn N. Freeman-Benson; Alan Borning (OOPSLA, 1994)