Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, khau sach
sang tay » sang tao, sang tai, sang tac
cham duc » pham duc, cham soc, pham duy
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » su sach, te sach, tu cach
ty sang » ty xang, ty hang, duy sang
tay hoi » tay ho, tao hoi, tay thai
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
va hanh » van hanh, va thanh, va danh
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet

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) OR (thu hoach)))) ty sang tay hoi. hieu vu cham duc va hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (((thu sach) OR (thu hoach)))) ty sang tay hoi. hieu vu cham duc va hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (((thu sach) OR (thu hoach)))) ty sang tay hoi. hieu vu cham duc va hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((thu sach) OR (thu hoach)))) ty sang tay hoi. hieu vu cham duc va hanh lai cua tre*.