silkworm. Photography. Encyclopedia Britannica Image Quest. Web. 22 May 2013
Chinese Compass. Photography. Encyclopædia Britannica Image Quest. Web. 22 May 2013.
The Great Wall Of China. Photography. Encyclopædia Britannica Image Quest. Web. 22 May 2013.
6000, 2000 Year Old Teracotta Figures, Army Of Teracotta Warriors, Xian, Shaanxi
Province, China. Photography. Encyclopædia Britannica Image Quest. Web. 22 May 2013
History Alive!: The Ancient World. Palo Alto, CA: Teachers' Curriculum Institute, 2011
Chinese Compass. Photography. Encyclopædia Britannica Image Quest. Web. 22 May 2013.
The Great Wall Of China. Photography. Encyclopædia Britannica Image Quest. Web. 22 May 2013.
6000, 2000 Year Old Teracotta Figures, Army Of Teracotta Warriors, Xian, Shaanxi
Province, China. Photography. Encyclopædia Britannica Image Quest. Web. 22 May 2013
History Alive!: The Ancient World. Palo Alto, CA: Teachers' Curriculum Institute, 2011