Retrieved 2015-10-23. ↑ Twin-screw vs. Centrifugal Supercharging Kenne Bell ↑ "1923 Mercedes 6/25/40 hq". mercedes-benz-classic.com/content. Retrieved 2009-01-21. ↑ "Gottlieb Daimler, Wilhelm Maybach and the "Grandfather Clock"". benzinsider.com/2008. Retrieved 2009-01-21. ↑ "1923 Miller 122 Supercharged". sportscarmarket.com.