↑ de Hartog, Genghis Khan: Conqueror of the World, pp. 165–66: notes that contemporary Mongol sources describe Batu as invading with 12-14 tumens, which would give him a nominal total of 120,000-140,000 men. However, the author also notes that tumens were often at less than full strength.
↑ Fennell, John. "The Crisis of Medieval Russia: 1200-1304." Luân Đôn, 1983. Page 85. Excerpt: "If we assume that each of the larger cities could field, say, between 3,000 and 5,000 men, we can arrive at a total of about 60,000 fighting troops. If we add to this another 40,000 from smaller towns and from the various Turkic allies in the Principality of Kiev, then the total coincides with the 100,000 estimated by S.M. Solov'ev in his History o Russia. But then this is only a rough estimate of the potential number. We have no idea how many, towns and districts actually mustered troops- for instance, it seems highly unlikely that Novgorod sent any at all. Certainly none came to help their outpost at Torzhok. Perhaps then half or a quarter - or even a smaller fraction- of the total was the most the Russians could muster."
↑ Douglas, Robert Kennaway; Jülg, Bernhard (1911). “Mongols”. Trong Chisholm, Hugh. Encyclopædia Britannica18 (ấn bản 11). Nhà in Đại học Cambridge. tr. 712–721.
↑ Boris Rybakov, Киевская Русь и русские княжества XII-XIII вв. (Kievan Rus' and Russian Princedoms in 12th and 13th Centuries), Moskva: Nauka, 1993. ISBN5-02-009795-0.
