Citation Advantage of Open Access Articles
May 23rd, 2006 by John Wilbanks
“We found strong evidence that, even in a journal that is widely available in research libraries, OA articles are more immediately recognized and cited by peers than non-OA articles published in the same journal. OA is likely to benefit science by accelerating dissemination and uptake of research findings.
Of course, the whole article is online under a Creative Commons license.