Perhaps you should try some spelling variations:
dat thanh » dao thanh, dat khanh, dang thanh
thanh ve » hanh ve, thanh va, thanh vien
thuc dat » thuc vat, thuc dan, thuc day
nam thuc » nam thuoc, am thuc, nam thu
hieu van » thien van, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
nang xa » nang x, lang xa, nang ma
so sach » so sanh, bo sach, co sach
ve cuu » ve cau, ve chu, ve 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) or (so sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) nam thuc dat thanh ve cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (so sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) nam thuc dat thanh ve cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (so sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) nam thuc dat thanh ve cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (so sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) nam thuc dat thanh ve cuu tre*.