PLoS (2005). "Article-Level Metrics Information". PLoS ONE. 2005-07-01.
Bergstrom, C. T. (2007). "Eigenfactor: Measuring the value and prestige of scholarly journals". College & Research Libraries News 68 (5).
Falagas, M.E. et al (2008). "Comparison of SCImago journal rank indicator with journal impact factor". FASEB Journal 22 (8): 2623-2628.
Fersht, A. (Apr 2009). "The most influential journals: Impact Factor and Eigenfactor". Proceedings of the National Academy of Sciences of the United States of America 106 (17): 6883–6884.
Nelson, C and Wu, S. (2009). "Article-Level Metrics and the Evolution of Scientific Impact". PLoS Biology 7 (11).