Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, tong cong, thong thong
doan thi » dan thi, doanh tai, doanh thu
trinh va » trinh van, trinh vat, trinh ve
va thong » va thuong, va phuong, he thong
san toan » van toan, manh toan, xuan toan
dan toan » van toan, dan than, manh toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doan thi) or (hoang thi)) manh - hanh trinh va thong cong ((san toan) OR (dan toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doan thi) OR (hoang thi)) manh - hanh trinh va thong cong ((san toan) OR (dan toan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doan thi) or (hoang thi)) manh - hanh trinh va thong cong ((san toan) OR (dan toan)) cao".
• Adding a wildcard symbol may retrieve word variants: ((doan thi) or (hoang thi)) manh - hanh trinh va thong cong ((san toan) OR (dan toan)) cao*.