It should be noted that this paper was released before the Ada 95, Ada 2005, Ada...

It should be noted that this paper was released before the Ada 95, Ada 2005, Ada 2012, and soon-to-be Ada 2022 standards were published:

Ada 95: https://www.adahome.com/rm95/

Ada 2005: https://www.adaic.org/resources/add_content/standards/05rm/h...

Ada 2012: http://www.ada-auth.org/standards/12rm/html/RM-TTL.html

Ada 2022 (draft): http://www.ada-auth.org/standards/ada22.html

The paper's abstract states: "Although Ada supports concurrency and can thus be used as a concurrent programming language, it is not generally considered to be an object-oriented programming language."

Object-oriented programming was added in Ada 95, so this paper is probably not relevant to modern programming unless you are interested in the history of the Ada programming language.