Tham khảo Sông Opir

  1. 1 2 Prykhodko, M. M.; Romaniuk, V. V.; Kukhtar, D. V.; Bodnaruk, I. L.; Adamovych, M. V. (2020). “Use of geoinformation technology to study the structure and morphometric parameters of river basins”. Geoinformatics: Theoretical and Applied Aspects 2020: 1–5. doi:10.3997/2214-4609.2020geo014.
  2. ↑ Saul Bernard Cohen, Saul Cohen (2008). “Verkhnye Syn'ovydne”. The Columbia Gazetteer of the World: A to G. tr. 4092. ISBN 9780231145541.
  3. 1 2 3 4 5 Anna Hryhorivna Lutsyk, Pavlo Volodymyrovych Bosak (2019). “Антропогенне забруднення річок смт. Славське” [Anthropogenic pollution of rivers in the town of Slavske] (PDF). Проблеми та перспективи розвитку системи безпеки життєдіяльності (bằng tiếng Ukraina): 163–165.
  4. ↑ N.Ye. Pankiv, O.R. Roik (2019). “Greenways as a model for the development of sustainable tourism in the Lviv region”. Journal of Geology, Geography and Geoecology. 28 (1). doi:10.15421/111917. ISSN 2617-2909.