Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
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 cuu » lai cua, lai chau, lai cuoc
luc van » luoc van, luu van, duc van
van cam » van nam, van lam, van dam
van cau » van dau, van hau, van chat
nang ma » tang ma, sang ma, nang cao
cuu tre » cua tre, cau tren, cau treo

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