Perhaps you should try some spelling variations:
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
lang xa » dang xay, lang van
lai cua » dai cua, hai cua, lai chau
lang ha » long ha
va hanh » van hanh, va thanh, va danh
hieu ve » hieu van
truc va » thuc va, thuc vat, trung va
cua te » cua tu

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 y ((lang xa) OR (lang ha)) hoi. ((hieu ve) or (hieu va)) cau truc va hanh lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((lang xa) OR (lang ha)) hoi. ((hieu ve) OR (hieu va)) cau truc va hanh lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((lang xa) OR (lang ha)) hoi. ((hieu ve) or (hieu va)) cau truc va hanh lai cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((lang xa) OR (lang ha)) hoi. ((hieu ve) or (hieu va)) cau truc va hanh lai cua te*.