While there is no formal academic "paper" published in a scientific journal specifically titled "Joint Push Pull SketchUp 2021," the primary authoritative documentation for this extension is the Joint Push Pull User Manual authored by its creator, Official Documentation & Guides Joint Push Pull User Manual : This is the definitive technical guide provided by SketchUcation
: The primary tool for extruding multiple or curved faces simultaneously while automatically filling the "joints" between them. Vector Push Pull Joint Push Pull Sketchup 2021
Using Joint Push Pull in SketchUp 2021: A Step-by-Step Guide While there is no formal academic "paper" published