Galtung, J. (2007). The State of the World. Journal of Futures Studies, 12(1), 145-160. https://www.airitilibrary.com/Article/Detail?DocID=10276084-200708-12-1-145-160-a
Shek, K. Y. (2012). From cattle to people [master's thesis, The University of Hong Kong]. Airiti Library. https://www.airitilibrary.com/Article/Detail?DocID=U0029-1812201200020530