Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, chau tinh, kieu tinh
hanh trang » thanh trung, canh tranh, hanh trinh
nhung cong » dung cong, thong cong, hang cong
lieu tinh » trieu tinh, diep tinh, bien tinh
trang va » tran van, hang va
tan toan » tap toan, van toan, dan toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu tinh) OR (lieu tinh)) - hanh trang va nhung cong ((tan toan) or (tan tran)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu tinh) OR (lieu tinh)) - hanh trang va nhung cong ((tan toan) OR (tan tran)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu tinh) OR (lieu tinh)) - hanh trang va nhung cong ((tan toan) or (tan tran)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu tinh) OR (lieu tinh)) - hanh trang va nhung cong ((tan toan) or (tan tran)) cao*.