The US-EU race for leadership of science and technology: Qualitative and quantitative indicators. - Robert D. Shelton; Geoffrey M. Holdridge (Scientometrics, 2004)

China as Number 1? A Case for China Regaining World Leadership of Science and Technology. - Aparna Basu; Patricia Foland; Geoffrey M. Holdridge; Robert D. Shelton (ISSI, 2017)

China's rising leadership in science and technology: quantitative and qualitative indicators. - Aparna Basu; Patricia Foland; Geoffrey M. Holdridge; Robert D. Shelton (Scientometrics, 2018)