Perhaps you should try some spelling variations:
thuc dang » thuoc dang, thuc dan, thuc dung
dang hanh » dang thanh, ban hanh, dang van
hieu van » thien van, lieu va, hieu ve
hoi nang » ho nang, hoa nang, hoi dang
hanh doi » thanh doi, hanh noi, hang doi
hoi lang » hoa lang, hoi dan
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
doi cua » dai cua, hoi cua
ma hoi » mai hoi, xa hoi, ma hoa

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 ((hoi nang) or (hoi lang)) ma hoi. ((hieu van) or (hieu va)) am thuc dang hanh doi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((hoi nang) OR (hoi lang)) ma hoi. ((hieu van) OR (hieu va)) am thuc dang hanh doi cua vat.
• Adding a wildcard symbol may retrieve word variants: tu sach ((hoi nang) or (hoi lang)) ma hoi. ((hieu van) or (hieu va)) am thuc dang hanh doi cua vat*.