Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hang tai » hang va, dung tai
cham thu » cam thu, nham thu, pham thu
va hang » van hang, va nang, va lang
tu sach » thu sach, su sach, te sach
hieu va » lieu va
tu nano » truc nano
tu nang » tru nang, tu nong, tu lang
thu va » thuc va, thue va, tu va
tai su » tai so, tai tu, lai 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 sach ((tu nang) OR (tu nano)) xa hoi. ((hieu va) or (hieu qua)) cham thu va hang tai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tu nang) OR (tu nano)) xa hoi. ((hieu va) OR (hieu qua)) cham thu va hang tai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tu nang) OR (tu nano)) xa hoi. ((hieu va) or (hieu qua)) cham thu va hang tai su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tu nang) OR (tu nano)) xa hoi. ((hieu va) or (hieu qua)) cham thu va hang tai su triet*.