Perhaps you should try some spelling variations:
sach thuc » cach thuc, sach thu, sach thue
ban thanh » ban hanh, ban hang
thanh dai » thanh hai, thanh tai, thanh dat
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
hanh ca » hanh cac, hanh cat, hanh cua
cam duc » cam xuc, cao duc, nam duoc
cua tre » cua te, cuu tre, cua triet
ca hoi » cau hoi, cua hoi, xa hoi

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 thuc hanh ca hoi. hieu van ((cam duc) or (pham duc)) ban thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thuc hanh ca hoi. hieu van ((cam duc) OR (pham duc)) ban thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thuc hanh ca hoi. hieu van ((cam duc) or (pham duc)) ban thanh dai cua tre*.