Perhaps you should try some spelling variations:
hanh trang » thanh trung, canh tranh, hanh trinh
thieu sach » chieu sach, thien hach, hieu cach
nhung cong » thong cong, hang cong, nhung don
hoc thieu » toc thieu, hoc hien
hanh tang » anh tang, hanh mang, hanh tung
dung cong » dung trong
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap

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 - ((hanh tang) OR (hanh trang)) luan ((nhung cong) or (dung cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - ((hanh tang) OR (hanh trang)) luan ((nhung cong) OR (dung cong)) dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - ((hanh tang) OR (hanh trang)) luan ((nhung cong) or (dung cong)) dan toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - ((hanh tang) OR (hanh trang)) luan ((nhung cong) or (dung cong)) dan toan cao*.