Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
thieu xanh » chieu xanh, hieu manh, thien anh
tien anh » tieng anh, tien manh, dien anh
trinh va » trinh van, trinh vat, trinh ve
va trong » va truong, va thong, va tuong
dan toan » van toan, dan than, manh toan
tap toan » tap doan, tap quan, bai 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 ((thieu xanh) or (tien anh)) - hanh trinh va trong cong ((dan toan) or (tap toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (tien anh)) - hanh trinh va trong cong ((dan toan) OR (tap toan)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (tien anh)) - hanh trinh va trong cong ((dan toan) or (tap toan)) cau*.