Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
canh trinh » canh tranh, hanh trinh, canh tinh
dung cong » dung trong
trinh va » trinh van, trinh vat, trinh ve
tac toan » tap toan, tam toan, hach toan
toan tap » toan ban
ho lieu » so lieu, co lieu, ho chieu
ho kieu » so kieu, thi kieu, ho chieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho lieu) or (ho kieu)) tinh - canh trinh va ((nhung cong) OR (dung cong)) tac toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho lieu) OR (ho kieu)) tinh - canh trinh va ((nhung cong) OR (dung cong)) tac toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho lieu) or (ho kieu)) tinh - canh trinh va ((nhung cong) OR (dung cong)) tac toan tap".
• Adding a wildcard symbol may retrieve word variants: ((ho lieu) or (ho kieu)) tinh - canh trinh va ((nhung cong) OR (dung cong)) tac toan tap*.