“…The fundamental difference between nonlocal models and classical local models is the fact that the latter only involve differential operators (local equations), whereas the former rely on integral operators (nonlocal equations). For general references on nonlocal models and their applications to elasticity, population dynamics, image processing, etc., we refer the reader to [6,7,9,10,11,12,13,18,21,25,27,33,35,34,36,37,38] and the book [2].…”