Would like a recipe for Bell's Porter

Is there an authentic recipe from the brewery for Bell’s Porter?  I’d love to brew it.

Thanks

Thanks much.  I’ll give it a try the next time I brew-- probably about 6 weeks from now.  I’m aware that it’s difficult to exactly duplicate a brew because of all the variables, house yeast, different process etc., but at least I now know what the recommended ingredients and how much of them to start with.