Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
ho chieu » theo chieu, hoc thieu, doi chieu
trinh va » trinh van, trinh vat, trinh ve
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
doi chi » doi khi

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 (doi chi)) xanh - hanh trinh va ((hang cong) OR (dang cong)) tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chi)) xanh - hanh trinh va ((hang cong) OR (dang cong)) tac toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (doi chi)) xanh - hanh trinh va ((hang cong) OR (dang cong)) tac toan cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doi chi)) xanh - hanh trinh va ((hang cong) OR (dang cong)) tac toan cau*.