Researchr is a web site for finding, collecting, sharing, and reviewing scientific publications, for researchers by researchers.
Sign up for an account to create a profile with publication list, tag and review your related work, and share bibliographies with your co-authors.
Loet Leydesdorff, Caroline S. Wagner. Is the United States losing ground in science? A global perspective on the world science system. Scientometrics, 78(1):23-36, 2009. [doi]
Abstract is missing.