Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh cao » trinh chao, trinh co, trinh cau
nang cong » nang song, dang cong, hang cong
bang cong » dang cong, bang song, hang cong
theo chu » theo chieu, cho chu, chao chu
tac toan » tap toan, tam toan, hach 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: ((theo chu) or (theo tieu)) xanh - hanh trinh cao ((nang cong) OR (bang cong)) tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chu) OR (theo tieu)) xanh - hanh trinh cao ((nang cong) OR (bang cong)) tac toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chu) or (theo tieu)) xanh - hanh trinh cao ((nang cong) OR (bang cong)) tac toan cau".
• Adding a wildcard symbol may retrieve word variants: ((theo chu) or (theo tieu)) xanh - hanh trinh cao ((nang cong) OR (bang cong)) tac toan cau*.