Sun YL, Obertelli A, Doornenbal P, Barbieri C, Chazono Y, Duguet T, Liu HN, Navrátil P, Nowacki F, Ogata K, et al. Restoration of the natural E (1/21+)-E (3/21+) energy splitting in odd-K isotopes towards N= 40. Physics Letters B. 2020;802:135215.