I am trying to find the literal source of these terms as 
Georgescu-Roegen used both of them in "activity analysis" in 1949, 
and Hicks used the former in his "neo-Austrian [growth] theory" in 
1970--and both in 1973.
         So far as I can tell from JSTOR and various books, the 
singular ("elementary process") was a common term in English in 
psychology and physical chemistry from the late 19th century, and the 
plural ("elementary processes") an occasional term in English for 
quasi-engineering analysis of production from 1909.
Georgescu-Roegen could well have adopted the terms in English or in 
German or in French, "Elementarprozess(e)," "processus 
elementaire(s)," from physical chemistry. But this is only a guess.
         Hicks in this regard is a mystery to me. It was evidently 
not until after he had used the term (singular in 1970, both singular 
and plural in 1973) that he first read (or at least thought seriously 
about) Georgescu-Roegen. In 1973, in Capital and Time (p. 7) he 
refers to Boehm-Bawerk as if he were drawing the terms from him, in 
particular from "The Positive Theory of Capital (1889)," i.e., 
Kapital und Kapitalzins (1889). There is a lot of "process," but I 
cannot find any of it distinguished as "elementary," in English or German.
         Can anyone on the list who knows this literature advise me 
where I might best look for the source, more likely the sources, for 
these terms and this usage, in either Georgescu-Roegen's or Hicks's 
case, or both?
         Thanks in advance for any help.

John Womack