Roy Salvadori ขับรถให้กับ David Brown Corporation ในรอบใด?ไม่จำเป็นต้องใช้ตารางทั้งหมด
What rounds did Roy Salvadori drive for David Brown Corporation?It is not neccessary to use all the tables.
 table_name_98:  rounds [ VARCHAR]  entrant [ VARCHAR]  driver [ VARCHAR] 
SELECT rounds FROM table_name_98 WHERE entrant = "david brown corporation" AND driver = "roy salvadori"