Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
vat thanh » dat thanh, gat thanh, tat thanh
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
van cam » van nam, van lam, van cau
cuc tre » duc tre, cua tre, cuu tre

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky ((mang may) or (nang ma)) hoi. hieu van cam thuc vat thanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((mang may) OR (nang ma)) hoi. hieu van cam thuc vat thanh tai cuc tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((mang may) or (nang ma)) hoi. hieu van cam thuc vat thanh tai cuc tre*.