Perhaps you should try some spelling variations:
sach tham » sach nha
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
chua tre » chua tri, cua tre, chua trieu
lang ha » long ha
sach tu » sach thu, cach tu, sach ty
thuc va » thuc vat, thuc dan, thuc day
dinh va » dinh van, tinh va, sinh va
dinh ve » dinh ket, dinh van
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach tu) or (sach tham)) lang ha hoi. hieu van nam thuc va ((dinh va) or (dinh ve)) chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach tu) OR (sach tham)) lang ha hoi. hieu van nam thuc va ((dinh va) OR (dinh ve)) chua tre.
• Adding a wildcard symbol may retrieve word variants: toc ((sach tu) or (sach tham)) lang ha hoi. hieu van nam thuc va ((dinh va) or (dinh ve)) chua tre*.