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Before the 1940s the terms "system" and "systems thinking" had been used by several scientists, but it was Bertalanffy's concepts of an open system and a general systems theory that established systems thinking as a major scientific movement

Fritjof Capra, Pier Luigi Luisi (2014). “The Systems View of Life: A Unifying Vision”, p.85, Cambridge University Press
Before the 1940s the terms system and systems thinking had been used by several scientists, but it was Bertalanffy's concepts of an open system and a general systems theory that established systems thinking as a major