Perhaps you should try some spelling variations:
nhien viet » nhin viet, nghiep viet, trien viet
nhieu viec » hieu viec
thuc cao » thuoc cao, thuc co, thuc can
dan thuc » dan toc, am thuc
doan vi » doan va, doan thi, doan van
te sach » toc sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
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 ty nang xa hoi. ((nhieu viec) OR (nhien viet)) dan thuc cao ((doan vi) or (don vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang xa hoi. ((nhieu viec) OR (nhien viet)) dan thuc cao ((doan vi) OR (don vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang xa hoi. ((nhieu viec) OR (nhien viet)) dan thuc cao ((doan vi) or (don vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang xa hoi. ((nhieu viec) OR (nhien viet)) dan thuc cao ((doan vi) or (don vi)) cua tre*.