Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
dai danh » dai dang, dao danh, day danh
xay danh » day danh, vay doanh, xay dung
hieu van » hieu va, thien van, lieu va
ban cua » ban quan
sach ky » sac ky, sach ty, sach kem
cao hoi » cau hoi, co hoi, cao hoc
cua tre » cua te, cuu tre, cua triet

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 ky) OR (sach y)) nang cao hoi. hieu van nam thuc ((xay danh) or (dai danh)) ban cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) nang cao hoi. hieu van nam thuc ((xay danh) OR (dai danh)) ban cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sach y)) nang cao hoi. hieu van nam thuc ((xay danh) or (dai danh)) ban cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sach y)) nang cao hoi. hieu van nam thuc ((xay danh) or (dai danh)) ban cua tre*.