Testing and selecting cosmological models with ultra-compact radio quasars Xiaolei Li, Shuo Cao, Xiaogang Zheng, Jingzhao Qi, Marek Biesiada and Zong-Hong Zhu Eur. Phys. J. C, 77 10 (2017) 677 Published online: 13 October 2017 DOI: 10.1140/epjc/s10052-017-5238-2