Motocross, Supercross. 1970's. - Dave's Tests and Articles
The Birth of Motocross: An Illustrated History of the Early Years of America's #1 Dirt Sport - The Tracks - The Riders - The Machines: Schleicher, Robert: 9781583883310: Amazon.com: Books
Honda MX Bike History Pt 1: The 1970s – PulpMX
Motocross Superstars of the 1970's 1980's And 1990's
Motocross 1970
Documentary: Victory For Suzuki - The 1970 Grand Prix Motocross Season
File:Yamaha motocross bike 1970s.jpg - Wikimedia Commons
Vintage Motocross 1972 Crossed Up Yamaha Poster Original 1970's Motorcycle | eBay