Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
tang van » dang van, hoang van, trong van
hanh lai » hanh lam, hanh tai, thanh lap
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
lai cua » dai cua, hai cua, lai chau
cac cuu » cap cuu, cac cau, cac chu
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
tang ma » mang may

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 (thuoc sach)) ky ((tang ma) OR (tang van)) hoa. hieu va cac cuu van hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky ((tang ma) OR (tang van)) hoa. hieu va cac cuu van hanh lai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) ky ((tang ma) OR (tang van)) hoa. hieu va cac cuu van hanh lai cua tre*".