Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
cao sang » cao dang, cao tang, cao bang
nam thuc » nam thuoc, am thuc, nam thu
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
lo sang » lam sang, luc sang, lee sang
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua

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