Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
tu sach » thu sach, su sach, te sach
toc gia » toc giay, tac gia, quoc gia
viec va » vien va, viec cua, viec lam
y sang » _ sang, duy sang
va toc » va doc, va tac, va tuc
ma hoi » mai hoi, xa hoi, me hoi
va cuu » va chu, va huu
va cau » van cau, va cac, va dau

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 y sang ((ma hoi) or (ma hoa)). hieu viec va toc gia thanh ((va cuu) OR (va cau)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y sang ((ma hoi) OR (ma hoa)). hieu viec va toc gia thanh ((va cuu) OR (va cau)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y sang ((ma hoi) or (ma hoa)). hieu viec va toc gia thanh ((va cuu) OR (va cau)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y sang ((ma hoi) or (ma hoa)). hieu viec va toc gia thanh ((va cuu) OR (va cau)) tre*.