Tobit Regression

I'm statistician
I have thesis : Tobit Regression
my book : Greene, William H. 1997. Econometric Analysis. Third
Edition, prentice Hall
Is there the program in R ?
may I ask the manual how make the program? and also how to test the assumption ?
If there are anyone have Amemiya journal may I asked ?

please help me! I already googling and I don't get the answer.
Before i use STATA 6 to analyze. but I don't get the manual.