Mobjectivist blogspot
Try this one. Hubbert tried to fit the logistic function to the oil data, and also used the verhulst function noted in the article.
Either will be close enough given the data that we are all working with.
Also, if you go to
www.graphoilogy.com, and email Khebab, he will help you. He occasionally still posts here, and also posts on The Oil Drum, and has tried to fit various functions to the Hubbert data.
Roper
David Roper is a former prof at Va Tech who applied the Hubbert technique to various other ores and materials, and this may be helpful to you.
http://www.peakoil.com/fortopic10625.html
We did a lot of work in this thread on the verhulst and other models, comparing them for error, etc.
http://www.peakoil.com/fortopic9205.html
Khebab provided this thread modeling delpletion based on the Ricatti formula.
http://www.peakoil.com/fortopic8868.html
Here is a thread where we tried to debug the verhulst model and refine our method a little bit.
Anyway, this should give you a start. If you learn something interesting, try to come back and explain it to us.