Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
nay lang » nam lang, tay lang, nhan lang
hanh vai » hanh vi, hanh va, hanh tai
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cau loc » hau loc, cau hoc, cau luc
cua tre » cua te, cuu tre, cua triet
lang ha » long ha
hieu ve » hieu van
loc va » hoc va, luc va
ha hoi » hoa hoi, ha noi, xa hoi

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