 Complete the following phrase:  Spain did not return to the international calendar until 1951, joining the list of races of the Formula One championship at the very wide Pedralbes street circuit in Barcelona. Argentine Juan Manuel Fangio won his first world championship at the 1951 event in an Alfa Romeo while he took advantage of the improved works Ferraris tire problems. The race was scheduled for the 1952 and 1953 seasons but did not take place due to a lack of money, and in 1954, Briton Mike Hawthorn stopped Mercedess domice by winning in a Ferrari. In 1955, the Spanish Grand Prix at Pedralbes was scheduled to take place, but a 