@article{Ragul’skii:1997,
	author = {V. V. Ragul’skii},
	title = {An experimental study of the optical isotropy of space
},
	publisher = {Physics-Uspekhi},
	year = {1997},
	journal = {Phys. Usp.},
	volume = {40},
	number = {9},
	pages = {972-974},
	url = {https://ufn.ru/en/articles/1997/9/j/},
	doi = {10.1070/PU1997v040n09ABEH001573}
}