1. Burns, A.: The Ravenscar Profile. Ada Letters, XIX:4. ACM Press (1999) 49–52.
2. Lect Notes Comput Sci;S.T. Taft,1997
3. Lect Notes Comput Sci;J.A. Puente de la,2000
4. Ada Core Technologies Inc.: GNAT web page. http://www.gnat.com
5. Vardanega, T., Terraillon, J.-L. (ed.): Proceedings of the Seminar: The Role of Open-Source Software in the Space Business Technical Issues, Use Guidance, Legal Implications. European Space Agency (2000). ftp://ftp.estec.esa.nl/pub/ws/opensource/OpenSourceSeminar.htm