Consider the functions $f : X \to Y$ and $g : Y \to Z$. According to the Wikipedia articles on Function Composition, the application of $f$ to an input $x$ can be written as $xf$ (as opposed to the usual $f(x)$), and function composites can be written as $fg$ (as opposed to the usual $g \circ f$). This is known as postfix notation or diagrammatic notation because the equation $(xf)g = x(fg)$ holds and the function composite can be read from the following diagram: $$ X \xrightarrow{f} Y \xrightarrow{g} Z \implies X \xrightarrow{fg} Z $$
I would like a journal reference that uses this notation, preferably briefly explaining its advantages.
What I've tried
The closest reference I have is "Z Notation", where relations $R \subseteq X \times Y$ and $S \subseteq Y \times Z$ can be composed in diagrammatic order using a "fat semicolon":
This use of semicolon coincides with the notation for function composition used (mostly by computer scientists) in Category theory.
Could I also have a journal reference that uses Z notation?
Not sure if this is exactly what you're looking for, but this blog post has three references to Journal articles about reverse Polish notation (postfix notation).