David Spivak: 18.S996 Category Theory for Scientists, Spring 2013.
(Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed 25 May, 2015). License: Creative Commons BY-NC-SA
(Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed 25 May, 2015). License: Creative Commons BY-NC-SA