Price Digests, an equipment and vehicle data company, produces "The Official Tractor Blue Book" for used and new tractors in print form and an online subscription at TractorBlueBook.com. The book lists approximately 75 years of tractor models in over 50 brands.
"The Official Tractor Blue Book" includes possible retail values for new tractors, and for used tractors, it provides a range of possible retail and trade-in prices. Each model listing contains useful specifications, such as engine size and horsepower. The book also includes a serial number identification section, which allows tractor owners to find the year their tractor was made.