Apply Join Between Three Sharepoint List

Hello All ,

How can I apply Join Between Three Sharepoint List by List Name .. I gone through the below articles but I am not able to understand in my scenario .

http://espidi.com.au/blogs/left-join-with-multiple-lists-in-sharepoint-2010caml-and-linq/

http://www.chaholl.com/archive/2010/03/12/joins-in-linq-to-sharepoint-2010.aspx

In my case .. I am haiving three Sharepoint list :

List A : Title ,ID

List B: Product Name , ID, RefId (Lookup of List A Id Column)

List C: Prices,ID, RefId (Lookup of List A Id Column)

I want to pass ID of List A , Product Name  of List B and Price of List C using CAML query and get the records from all three list ..

Could any one help me to resolve this.