@article{Okonov:1969,
	author = {E. O. Okonov},
	title = {Mass differences of KL and KS mesons},
	publisher = {Physics-Uspekhi},
	year = {1969},
	journal = {Phys. Usp.},
	volume = {11},
	number = {4},
	pages = {521-521},
	url = {https://ufn.ru/en/articles/1969/4/m/},
	doi = {10.1070/PU1969v011n04ABEH003794}
}