Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
hanh tang » hanh trang, anh tang, hanh mang
tang luan » dung luan
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
ho chieu » theo chieu, doi chieu, mot chieu
tan toan » tan tran, tap toan, van toan
toan cau » 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: ((ho chieu) or (hoc thieu)) sach - hanh tang luan ((hang cong) OR (dang cong)) tan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) sach - hanh tang luan ((hang cong) OR (dang cong)) tan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc thieu)) sach - hanh tang luan ((hang cong) OR (dang cong)) tan toan cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) sach - hanh tang luan ((hang cong) OR (dang cong)) tan toan cau*.