pdf Philip J. Adler, Randall L. Pouwels – World Civilizations. Sixth Edition -Wadsworth Publishing (2012).pdf
pdf Curtis, Kenneth R._Hansen, Valeri – Voyages in World History-Wadsworth Publishing co inc (2014).pdf
pdf Merry Wiesner-Hanks & Patricia Buckley Ebrey & Roger Beck & Jerry Davila & Clare Crowston & John P. McKay – A History of World Societies, Combined-Bedford Books (2017).pdf
pdf Richard Bulliet, Pamela Kyle Crossley, Daniel Headrick, Steven Hirsch, Lyman Johnson, David Northup – The Earth and Its Peoples_ A Global History -Cengage Learning (2010).pdf
