[国外标准] SAE J875-1999 Trailer Axle Alignment
[国外标准] SAE J847-1987 TRAILER TOW BAR EYE AND PINTLE HOOK／COUPLER PERFORMANCE
[国外标准] SAE J684-1998 Trailer Couplings,Hitches,and Safety Chains.Automotive Type
[国外标准] SAE J1452-2002 Trailer Grade Parking Performance Test Procedure