Refernce Book for Buick Twenty One Six Cylinder Models, original operator's owner's manual and service manual.  Series twenty one models are illustrated briefly in the front.  Item is used, but in good usable condition.  Read about the operation, lubrication, power plant, fuel system, etc.  Includes 26 illustrated diagrams/plates, as well as an addendum on battery storage.  Cover is printed 1921 and restamped 1922.