The statement that a hanging chain (catenary) assumes the shape that minimizes its total gravitational potential energy is a matter of classical physical mechanics and basic calculus of variations, requiring no citation.
The retrieved papers deal with unrelated topics such as historical modeling games, power line image processing, bio-inspired metaheuristic algorithms, reformulations of mechanics, and the mass of potential energy. None of the papers evaluate the physical properties of a hanging chain or catenary curve versus the area beneath it. However, the claim itself is a well-established physical principle of minimum potential energy in mechanics, making it common knowledge where no citation is required.