Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
canh trinh » canh tranh, hanh trinh, canh tinh
bien tinh » bi tinh, yen tinh, diep tinh
hach toan » thanh toan, manh toan
trinh ve » trinh he, trinh va, trinh vi
ve nhung » va nhung, tu nhung
tam toan » tap toan, tam than, pham toan
so bien » mot bien

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

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