* Korotayev A. & Khaltourina D. ''Introduction to Social Macrodynamics: Secular Cycles and Millennial Trends in Africa.'' Moscow: URSS, 2006. ISBN 5-484-00560-4 [http://urss.ru/cgi-bin/db.pl?cp=&lang=en&blang=en&list=14&page=Book&id=37485]. | * Korotayev A. & Khaltourina D. ''Introduction to Social Macrodynamics: Secular Cycles and Millennial Trends in Africa.'' Moscow: URSS, 2006. ISBN 5-484-00560-4 [http://urss.ru/cgi-bin/db.pl?cp=&lang=en&blang=en&list=14&page=Book&id=37485]. |