Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu hang » thi hang, thuc hanh, thu huong
phat duy » pham duy, phat huy, phan duy
van hanh » van thanh, ban hanh, van anh
hanh lai » hanh lam, hanh tai, thanh lap
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
duy van » duy vat, dung van
lai cua » dai cua, hai cua, lai chau
va hoi » xa hoi, va hoc
va hoa » van hoa, va hoc, ma hoa
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach thu hang ((va hoi) or (va hoa)). hieu va phat duy van hanh lai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu hang ((va hoi) OR (va hoa)). hieu va phat duy van hanh lai cua tu.
• Adding a wildcard symbol may retrieve word variants: so sach thu hang ((va hoi) or (va hoa)). hieu va phat duy van hanh lai cua tu*.