Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hanh tranh » canh tranh, hanh trang, lanh tranh
nhung cong » dung cong, thong cong, hang cong
chi danh » chi dan, chi anh, chi dinh
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
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: doi chi danh - ((hanh tranh) or (hanh trinh)) va nhung cong tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chi danh - ((hanh tranh) OR (hanh trinh)) va nhung cong tap toan cao.
• Adding a wildcard symbol may retrieve word variants: doi chi danh - ((hanh tranh) or (hanh trinh)) va nhung cong tap toan cao*.