CREATE TABLE table_52992 ("Constructor" TEXT, "Chassis" TEXT, "Engine" TEXT, "Tyres" TEXT, "Driver" TEXT, "Rounds" TEXT)

Who was the constructor of the car that Jan Lammers made 7-14 rounds in?
SELECT "Constructor" FROM table_52992 WHERE "Driver" = 'jan lammers' AND "Rounds" = '7-14'
SELECT "Constructor" FROM "table_52992" WHERE "Driver" = 'jan lammers' AND "Rounds" = '7-14'