Klein 1/4" Screwdriver HD Square Shank(94-600-4) | Linemen's Supply
P.L. Robertson, a Canadian, invented a square-socket drive which bears his name. Vintage Robertson screwdriver set, circa 1960. Wooden handles with original paint and still in working condition. : r/BuyItForLife
Choosing the Right Screwdriver Bit - iFixit Repair Guide
2 Square Screwdriver with 4-Inch Round Shank - 662 | Klein Tools
Screwdriver - Wikipedia
Q & A: Square Drive vs. Phillips-Head Screws | Popular Woodworking