[http://toyhouse.ie.tsinghua.edu.cn/wiki/index.php?title=XLP_White_Paper:_How_Teachers_and_Students_Built_a_New_World]Andrea Li, Zimmer Barnes, Benjamin Hsueh-Yung Koo[[XLP White Paper: How Teachers and Students Built a New World]] 2015.4
[[http://toyhouse.ie.tsinghua.edu.cn/wiki/index.php?title=Preamble]]Benjamin Koo, [[Preamble]] on ToyhouseWiki