Barbey, S;M. Kempe, and A. Strohmeier.«Object-Oriented Programming with Ada 9X».Draft Technical Report.Swiss Federal Institute of Technology in Lausanne Software Engineering Laboratory,1993[Consulta: 15 desembre 2013].«Ada 83 itself is generally not considered to be object-oriented; rather, according to the terminology of Wegner [Weg 87], it is said to be object-based, since it provides only a restricted form of inheritance and it lacks polymorphism.»