The Simplo was an American automobile manufactured from 1908 until 1909 by the Cook Motor Vehicle Company in St. Louis. A 10/12 hp twin-cylinder friction-drive runabout with a friction transmission and double chain drive, it sold for $600 and featured a detachable rumble seat.
- Automobile Manufacturers Worldwide Registry. McFarland. 17 November 2015. pp. 74–. ISBN 978-1-4766-1140-2.
- "The Simplo Automobile & The Cook Motor Vehicle Co".
- David Burgess Wise, The New Illustrated Encyclopedia of Automobiles.