Perhaps you should try some spelling variations:
nhieu viec » nhien viet
hieu viec » hieu ve, sieu viet, hieu hien
bieu hien » dieu hien, dieu khien, bien phien
su sach » so sach, vu sach
cac dai » cac dan, cac bai, can dai
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
dai va » mai va
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang x hoi. ((((hieu viec) OR (nhieu viec))) or (bieu hien)) cac dai va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x hoi. ((((hieu viec) OR (nhieu viec))) OR (bieu hien)) cac dai va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. ((((hieu viec) OR (nhieu viec))) or (bieu hien)) cac dai va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. ((((hieu viec) OR (nhieu viec))) or (bieu hien)) cac dai va hanh vi cua tre*.