Perhaps you should try some spelling variations:
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
hanh trung » thanh trung, hanh trang, manh trung
nhung cong » dung cong, thong cong, nhung don
trung cap » truong cao, trung tam
hang cong » dang cong, hang nong, bang cong
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sach) OR (thien hach)) - hanh trung cap ((nhung cong) or (hang cong)) dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien hach)) - hanh trung cap ((nhung cong) OR (hang cong)) dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) OR (thien hach)) - hanh trung cap ((nhung cong) or (hang cong)) dan than cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) OR (thien hach)) - hanh trung cap ((nhung cong) or (hang cong)) dan than cau*.