Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
nhung cong » dung cong, thong cong, hang cong
lieu tinh » diep tinh, bien tinh
trinh ve » trinh he, trinh va, trinh vi
ve nhung » va nhung, tu nhung
tac toan » tap toan, hach toan, tich toan
tam toan » tap toan, tam than, pham toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((lieu tinh) or (trieu tinh)) - canh trinh ve nhung cong ((tac toan) or (tam toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((lieu tinh) OR (trieu tinh)) - canh trinh ve nhung cong ((tac toan) OR (tam toan)) cao.
• Adding a wildcard symbol may retrieve word variants: so ((lieu tinh) or (trieu tinh)) - canh trinh ve nhung cong ((tac toan) or (tam toan)) cao*.