Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
cac thuc » cach thuc, can thuc, cay thuc
hanh lai » hanh lam, hanh tai, thanh lap
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cac thu » cach thuc, cac thoi
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: toc sach thi nang ma hoa. hieu va ((cac thuc) or (cac thu)) va hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thi nang ma hoa. hieu va ((cac thuc) OR (cac thu)) va hanh lai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach thi nang ma hoa. hieu va ((cac thuc) or (cac thu)) va hanh lai cua tre*.