Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
bien cac » vien cac, dien cac, bien ca
bieu cua » dieu cua, hieu cua, ben cua
tung cua » trung cua, tuong cua, tang cua
dung cua » dung luan, dung cho
cong ban » cong bang, cong san, cong tan
ban toan » bai toan, ban than, van toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((bien cac) or (bieu cua)) - thanh ((tung cua) OR (dung cua)) nhung cong ban toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((bien cac) OR (bieu cua)) - thanh ((tung cua) OR (dung cua)) nhung cong ban toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((bien cac) or (bieu cua)) - thanh ((tung cua) OR (dung cua)) nhung cong ban toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((bien cac) or (bieu cua)) - thanh ((tung cua) OR (dung cua)) nhung cong ban toan cao*.