Two typed copies of a manuscript titled, "A discussion of the concept of modules in programming systems" by Donald Cowan as well as C.J. Lucena and A. von Staa, Departamento de Informática, Pontifícia Universidade Católica, Rio de Janeiro, Brazil. Both copies (original and photocopy) of the manuscript are twelve pages.

Two copies of a report titled, "On the concept of modules in programming systems" by Donald Cowan as well as C.J. Lucena and A. von Staa (Departamento de Informática, Pontifícia Universidade Católica, Rio de Janeiro, Brazil). The report was published by the Faculty of Mathematics at the University of Waterloo as Research Report CS-76-05 in January 1976. The report is thirty-nine pages.

A report titled, "The development proposal - the first step in software system construction," by Donald Cowan and A.Von Staa (Departamento de Informática, Pontifícia Universidade Católica, Rio de Janeiro, Brazil). The report was published by the Faculty of Mathematics at the University of Waterloo as Research Report CS-78-31 in June 1978. The cover page of the report includes a note that the research was supported in part by Canadian National Research Council Grant A2655. The report is seventy-six pages.