Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hang tai » hang va, dung tai
cua tre » cua te, cuu tre, cua triet
va hang » van hang, va nang, va lang
cac tuc » cac toc, cac tu, cac tac
hieu va » lieu va, hieu qua
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
tuc va » thuc va, truc va, tuc xa
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ((ky lang) OR (ky tang)) xa hoi. hieu va cac tuc va hang tai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ((ky lang) OR (ky tang)) xa hoi. hieu va cac tuc va hang tai ((cua tre) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ((ky lang) OR (ky tang)) xa hoi. hieu va cac tuc va hang tai ((cua tre) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: tu sac ((ky lang) OR (ky tang)) xa hoi. hieu va cac tuc va hang tai ((cua tre) or (su triet))*.