Perhaps you should try some spelling variations:
hieu ve » hieu va, hieu van
duc gia » quoc gia
tang ma » tang van
cam duc » cam xuc, cao duc, pham duc
su tai » su thi, tu tai
tai ky » thai ky, trai ky, sai ky
ve cam » ve cham, ve cac, va cam
vi su » va su, ve su, oi su
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su tai ky ((mang may) or (tang ma)) hoi. hieu ve cam duc gia thanh ((vi su) OR (ki su)) tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su tai ky ((mang may) OR (tang ma)) hoi. hieu ve cam duc gia thanh ((vi su) OR (ki su)) tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su tai ky ((mang may) or (tang ma)) hoi. hieu ve cam duc gia thanh ((vi su) OR (ki su)) tien".
• Adding a wildcard symbol may retrieve word variants: su tai ky ((mang may) or (tang ma)) hoi. hieu ve cam duc gia thanh ((vi su) OR (ki su)) tien*.