Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh chat » tinh chat, trinh luat, trinh han
chat nhung » chat ngung, thuat nhung, cua nhung
nhung cong » dung cong, thong cong, hang cong
tac toan » tam toan, hach toan, tich toan
tap toan » tap doan, tap quan, bai toan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc thieu) OR (hoc hien)) xanh - hanh trinh chat nhung cong ((tac toan) OR (tap toan)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc thieu) or (hoc hien)) xanh - hanh trinh chat nhung cong ((tac toan) OR (tap toan)) cao~".
• Adding a wildcard symbol may retrieve word variants: ((toc thieu) or (hoc hien)) xanh - hanh trinh chat nhung cong ((tac toan) OR (tap toan)) cao*.