OA in Physics Arxiv Yields Five-Fold Citation Advantage
(1) Making research papers open access (OA) dramatically increases their impact. (2) The earlier that papers are made OA, the greater their impact. (3) High Energy Physics (HEP) researchers were among the first to make their papers OA (since 1991, and they did it without needing to be mandated to do it!) (4) Gold OA provides no further impact advantage over and above Green OA.