Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh de, thanh do
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
luc va » duc va, tuc va
loc va » hoc va
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua

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 ky nang ma hoi. ((hieu ve) or (hieu va)) cam ((loc va) OR (luc va)) thanh di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. ((hieu ve) OR (hieu va)) cam ((loc va) OR (luc va)) thanh di cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoi. ((hieu ve) or (hieu va)) cam ((loc va) OR (luc va)) thanh di cua vat".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. ((hieu ve) or (hieu va)) cam ((loc va) OR (luc va)) thanh di cua vat*.