Amazon.com: Duncan Toys ProYo Looper Yo-Yo, Beginner Yo-Yo with String, Wooden Axle and Plastic Body, Mystery Color : Toys & Games
Duncan 1955 Super Tournament Wooden Yo Yo
World's Smallest - Duncan Imperial Yoyo – The Red Balloon Toy Store
vintage Duncan wood yo-yo and spinning tops, old wooden toys lot
Duncan Wooden Crossed Flags Tournament Yo-Yo – Growing Tree Toys
Smithsonian - Duncan Genuine Yo-Yo, 1930s America owes its fascination with the yo-yo mainly to Chicago businessman Donald F. Duncan Sr., who spotted it while on a business trip to San Francisco