https://elib.psu.by/handle/123456789/3918 Fri, 09 Oct 2026 03:13:42 GMT 2026-10-09T03:13:42Z https://elib.psu.by/handle/123456789/28520 Title: _ Authors: _ Sat, 01 Jan 2000 00:00:00 GMT https://elib.psu.by/handle/123456789/28520 2000-01-01T00:00:00Z https://elib.psu.by/handle/123456789/24287 Title: _ Authors: _ Sat, 01 Jan 2000 00:00:00 GMT https://elib.psu.by/handle/123456789/24287 2000-01-01T00:00:00Z https://elib.psu.by/handle/123456789/24286 Title: _ Authors: _ Sat, 01 Jan 2000 00:00:00 GMT https://elib.psu.by/handle/123456789/24286 2000-01-01T00:00:00Z https://elib.psu.by/handle/123456789/24281 Title: _ Authors: _ Sat, 01 Jan 2000 00:00:00 GMT https://elib.psu.by/handle/123456789/24281 2000-01-01T00:00:00Z