Perhaps you should try some spelling variations:
dinh tinh » dinh kinh, ninh tinh, dinh thanh
ton giao » toan giao, hoc giao, so giao
tu mach » tu cach, tu manh, tu hach
tu hanh » du hanh, lu hanh, thuc hanh
tich so » tich bao, tinh son
vu dinh » quy dinh
tinh so » tinh son, tinh soc, dinh so

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((tu mach) or (tu hanh)) tich so - ton giao ) or ( vu dinh tinh so - ton giao ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu mach) OR (tu hanh)) tich so - ton giao ) OR ( vu dinh tinh so - ton giao )).
• Adding a wildcard symbol may retrieve word variants: (( ((tu mach) or (tu hanh)) tich so - ton giao ) or ( vu dinh tinh so - ton giao ))*.