Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec cac » vien cac, viec cua, viec lam
hanh hai » thanh hai, nhanh hai, hang hai
sach thu » sach thue, sach thieu, sach tham
hai cua » thai cua, dai cua, hoi cua
thuc va » thuc dan, thuc day
so sach » so sanh, bo sach, co sach
mang xa » lang xa, mang may, dang xay
lang ha » long ha
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach thu ((mang xa) or (lang ha)) hoi. hieu viec cac ((thuc va) OR (thuc vat)) hanh hai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu ((mang xa) OR (lang ha)) hoi. hieu viec cac ((thuc va) OR (thuc vat)) hanh hai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thu ((mang xa) or (lang ha)) hoi. hieu viec cac ((thuc va) OR (thuc vat)) hanh hai cua tu".
• Adding a wildcard symbol may retrieve word variants: so sach thu ((mang xa) or (lang ha)) hoi. hieu viec cac ((thuc va) OR (thuc vat)) hanh hai cua tu*.