Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
su triet » su viet, su tien, ve triet
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
van tang » van thang, van trang, van nang
bac van » bach van, cac van, ban van
cam luc » cam xuc, cau luc
tang ma » mang may, tang van
ma hoi » mai hoi, xa hoi, ma hoa
tu bac » tu ban, tu cac, tu bat
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: tu bac van tang ma hoi. ((hieu qua) or (hieu quan)) cam luc ((van hanh) or (ban hanh)) ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu bac van tang ma hoi. ((hieu qua) OR (hieu quan)) cam luc ((van hanh) OR (ban hanh)) ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu bac van tang ma hoi. ((hieu qua) or (hieu quan)) cam luc ((van hanh) or (ban hanh)) ki su triet*.