Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
vat hanh » vat thanh, van hanh, va hanh
cau thuc » cau truc, cuu thuc, can thuc
cua tre » cua te, cua triet, dua tren
hanh de » hanh ve, hanh kem
hieu va » lieu va, hieu qua
cuu tre » cau tren, cau treo
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach y ((nang ma) or (sang ma)) hoi. hieu va cau thuc vat hanh de ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y ((nang ma) OR (sang ma)) hoi. hieu va cau thuc vat hanh de ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: thuat sach y ((nang ma) or (sang ma)) hoi. hieu va cau thuc vat hanh de ((cua tre) or (cuu tre))*.