1. J.H. Christenson, J.W. Cronin, V.L. Fitch and R. Turlay, Evidence for the 2π decay of the $$ {K}_2^0 $$ meson, Phys. Rev. Lett. 13 (1964) 138 [INSPIRE].
2. NA48 collaboration, A precision measurement of direct CP-violation in the decay of neutral kaons into two pions, Phys. Lett. B 544 (2002) 97 [hep-ex/0208009] [INSPIRE].
3. KTeV collaboration, Precise measurements of direct CP-violation, CPT symmetry, and other parameters in the neutral kaon system, Phys. Rev. D 83 (2011) 092001 [arXiv:1011.0127] [INSPIRE].
4. LHCb collaboration, Observation of CP-violation in charm decays, Phys. Rev. Lett. 122 (2019) 211803 [arXiv:1903.08726] [INSPIRE].
5. Belle collaboration, Observation of large CP-violation in the neutral B meson system, Phys. Rev. Lett. 87 (2001) 091802 [hep-ex/0107061] [INSPIRE].