What is the birth date of the person who won his first Formula One victory at the 1968 British Grand Prix?
Jo Siffert Joseph Siffert (7 July 1936 – 24 October 1971) was a Swiss racing driver.
Alex Soler-Roig Alex Soler-Roig (] ; born 29 October 1931) is a former racing driver from Barcelona, Spain. He participated in 10 Formula One World Championship Grands Prix, debuting on 19 April 1970, and scored no championship points. He also participated in several non-Championship Formula One races.