Perhaps you should try some spelling variations:
hien hanh » dieu hanh
tong cong » cong cong, dung cong, dang cong
toc hien » hoc hien, toc mien, toc thieu
anh hang » anh hoang, anh hung, anh bang
hang cua » mang cua, hang ca, huong cua
van toan » van tuan, van tan, van thanh
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: toc hien hanh - anh hang cua ((trong cong) or (tong cong)) van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc hien hanh - anh hang cua ((trong cong) OR (tong cong)) van toan cau.
• Adding a wildcard symbol may retrieve word variants: toc hien hanh - anh hang cua ((trong cong) or (tong cong)) van toan cau*.