Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
hoc thieu » toc thieu, hoc hien
trinh han » trinh quan
van toan » van tuan, van tan, van thanh
tap toan » tap doan, tap quan, bai toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu xanh - hanh trinh han ((nhung cong) or (dung trong)) ((van toan) or (tap toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh trinh han ((nhung cong) OR (dung trong)) ((van toan) OR (tap toan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh trinh han ((nhung cong) or (dung trong)) ((van toan) or (tap toan)) cao*.