Extending the predictive power of perturbative QCD Bo-Lun Du, Xing-Gang Wu, Jian-Ming Shen and Stanley J. Brodsky Eur. Phys. J. C, 79 3 (2019) 182 Published online: 28 February 2019 DOI: 10.1140/epjc/s10052-019-6704-9