Perhaps you should try some spelling variations:
thien van » thi van
nam thuc » nam thuoc, am thuc, nam thu
thuc day » thuc dan, thuc vat
te sach » toc sach
hanh di » hanh vi, hanh de, hang di
lo nang » ho nang, ly nang, loai nang
nang ma » tang ma, sang ma, nang cao
hanh ve » hanh vi, hanh va, hanh kem
hieu va » lieu va, hieu qua
sach lo » sach dao, sach doi, sach hoi
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: te sach lo nang ma hoi. ((thien van) or (hieu va)) nam thuc day ((hanh di) or (hanh ve)) hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach lo nang ma hoi. ((thien van) OR (hieu va)) nam thuc day ((hanh di) OR (hanh ve)) hoa viet.
• Adding a wildcard symbol may retrieve word variants: te sach lo nang ma hoi. ((thien van) or (hieu va)) nam thuc day ((hanh di) or (hanh ve)) hoa viet*.