6. References
Norton, R.L. (2012). Design of Machinery: An Introduction to the Synthesis and Analysis of Mechanisms and Machines. New York, NY: McGraw-Hill.
Saka, K. (2007). Karakuri: How To Make Mechanical Paper Models That Move. New York, NY: St. Martins Griffin.
http://wiki.dtonline.org/index.php/Snail_Cam
https://en.wikipedia.org/wiki/Cam
https://www.cs.cmu.edu/~rapidproto/mechanisms/chpt6.html
, multiple selections available,