S Barbey, M. Kempe, and A. Strohmeier.: Object-Oriented Programming with Ada 9X. In: Draft Technical Report. Swiss Federal Institute of Technology in Lausanne Software Engineering Laboratory, 1993 (adahome.com [abgerufen am 15. Dezember 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.“
