Grinin L.E. Production Revolutions and Periodization of History: A Comparative and Theoretic-mathematical Approach. / Social Evolution & History. Volume 6, Number 2 / September 2007 [1] 20 Ocak 2012 tarihinde Wayback Machine sitesinde arşivlendi.
Grinin L.E. Production Revolutions and Periodization of History: A Comparative and Theoretic-mathematical Approach. / Social Evolution & History. Volume 6, Number 2 / September 2007 [1] 20 Ocak 2012 tarihinde Wayback Machine sitesinde arşivlendi.