1000 year old "wine" jar

[TheEngineer]

I walked into an antique store over the weekend and picked up an unusual looking pottery jar. Turns out to be a Tang Dynasty wine jar (618-900 AD) so this thing is about 1300 years old. I know the dealer and he gave me some history on it.

But now I'm curious. I've been scouring the net for information and between some phone calls know that this piece was created before porcelin was perfected so it is a kind of in-between piece (Pottery to Porcelin). Anyone know where I can fine more information on this area?