Graphical extensions for pseudo-code, PDLs, and source code
James H. Cross, Sallie V. Sheppard · 1988
The control structure diagram (CSD) is a new graphical notation intended to increase the comprehensibility of software described or defined with pseudo-code, PDL, or source code. The CSD is a simple graphical extension to these textual representations that provides for the explicit depiction of the control constructs and control flow at all relevant levels of abstraction. The CSD is supported by a fully operational prototype editor which is presently configured for Pascal or pseudo-code that uses the keywords of Pascal.