Mortimer B. Lipsett, “On Using the Extensional Device of Chain-Indexing to Describe and Analyze the Complexities of a Research Problem”, General Semantics Bulletin, 1949, №’s 1 & 2, pp. 8–9.
The upload contains a .zip archive with the memorandum published earlier in PDF, in Markdown format. The archive also includes digitized diagrams from the memorandum in .svg format.