Perrie & Pavlov 2014, p. 14, A confrontation on the River Ugra which took place in October 1480, between Grand Prince Ivan III and Akhmat Khan of the Great Horde, is often said to have marked the definitive end of the 'Tatar yoke'. Perrie, Maureen; Pavlov, Andrei (2014). Ivan the Terrible. Routledge. ISBN978-1-317-89468-1.
Moss 2003, p. 93, The khan expected to meet up with Lithuanian forces sent by King Casimir... Khan Akhmad waited for the Lithuanian troops, but (as in 1380) they never appeared. Moss, Walter G. (2003). A History of Russia Volume 1: To 1917. Anthem Press. ISBN978-1-84331-023-5.