USCKA-KOWALKOWSKA, Joanna. DIRECT SOLAR RADIATION AND ATMOSPHERIC TURBIDITY IN MIKOŁAJKI IN THE YEARS 1971–1980 AND 1991–2000. Bulletin of Geography. Physical Geography Series. Online. 1 December 2009. No. 2, pp. 19-33. [Accessed 1 July 2024]. DOI 10.2478/2319.