Perhaps you should try some spelling variations:
dam thuc » am thuc, dan thuc, dai thuc
nam thuc » nam thuoc, am thuc, nam thu
hanh tai » thanh tai, hang tai, han tai
tai cuu » tai cuc, tai buu, tai cua
va hanh » van hanh, va thanh, va danh
te sach » toc sach
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
cuu tre » cua tre, cau tren, cau treo
sach 7 » sach y, sach 2
dam tu » nam tu, cam tu, tam tu
ma hoi » mai hoi, xa hoi, ma hoa
7 tang » 6 tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach 7 tang ma hoi. hieu va ((((dam thuc) or (nam thuc))) or (dam tu)) va hanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach 7 tang ma hoi. hieu va ((((dam thuc) OR (nam thuc))) OR (dam tu)) va hanh tai cuu tre.
• Adding a wildcard symbol may retrieve word variants: te sach 7 tang ma hoi. hieu va ((((dam thuc) or (nam thuc))) or (dam tu)) va hanh tai cuu tre*.