article 2013 6 pages The evaluation of critical swimming speed in 12-year-old boys Ryszard Zarzeczny, Mariusz Kuberski, Agnieszka Deska, Dorota Zarzeczna, Katarzyna Rydz JournalHuman MovementDOI10.2478/humo-2013-0002Publication typeOriginal ResearchPopulationboys View on DOI ↗