27th Annotated

http://www.math.columbia.edu/~woit/wordpress/archives/000118.html

This website is talking about what he think and know with Chern. The important source is 

Some of his most important work concerned the topology and geometry of fiber bundles, and

its significance can be seen in the number of crucial ideas of this field that carry his name,

for instance: chern classes, the Chern character, Chern-Weil theory , the Chern-Simons secondary

 characteristic class.