Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
chau tinh » cuu tinh, ha tinh, cua tinh
nhung cau » chung cu, nhung bai, nhu cau
dung cong » dung trong
trinh va » trinh van, trinh vat, trinh ve
tan toan » tap toan, van toan, dan toan
ho chau » ha chau, ho chu, o chau

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

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