From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
List of four firms that have recently adopted a specific form of springing.
| Identifier | ExFiles\Box 65a\3\ scan0341 | |
| Date | 6th October 1932 guessed | |
| X. The following four firms have recently taken up this form of springing :- Delage. Peugeot Darracq Mathis. | ||