ZHANG, Ruda January 18, 2020:  Use probabilistic model, not probability model. [127e581]
ZHANG, Ruda November 24, 2017:  Reformat note on ECON615 [45ec059]
ZHANG, Ruda October 14, 2017:  Overwrite Simple Linear Regression as Statistical Learning [4eabf19]
Ruda Zhang August 07, 2016:  Replace tab with two spaces. [adaa87b]
Ruda Zhang June 26, 2016:  one sentence per line [e15360a]
Ruda Zhang June 26, 2016:  add category tag to wiki pages [a9b356c]
Ruda Zhang June 26, 2016:  use canonical filename and no internal H1 [eeca8ff]