Wójcik, Tomasz, and Jacek Boraś. “Battle of 6–7 September 1939 Between Lieutenant Colonel Marian Frydrych’s Detachment With wehrmacht’s 30th Infantry Division to Keep the Bridge in Uniejów ”. Biuletyn Uniejowski, vol. 9, Nov. 2020, pp. 23-57, doi:10.18778/2299-8403.09.02.