KEJNA, Marek and USCKA-KOWALKOWSKA, Joanna. Solar radiation variability at Koniczynka near Toruń (Central Poland) in the years 2003–2016. Bulletin of Geography. Physical Geography Series. Online. 17 December 2018. No. 15, pp. 27-40. [Accessed 18 August 2024]. DOI 10.2478/bgeo-2018-0013.