Detecting Primordial Gravitational Waves: a forecast study on optimizing frequency distribution of next generation ground-based CMB telescopeDeliang Wu, Hong Li, Shulei Ni, Zheng-Wei Li and Cong-Zhan LiuEur. Phys. J. C, 80 2 (2020) 139DOI: https://doi.org/10.1140/epjc/s10052-020-7652-0