Perhaps you should try some spelling variations:
theo chua » theo chu, ho chua, tho chu
dung cong » dung trong
cheo cua » cho cua, chuoi cua, co cua
trang va » tran van, hang va
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
tang va » tang van, thang va, tang vat

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((theo chua) or (cheo cua)) tinh - hanh ((tang va) OR (trang va)) dung cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chua) OR (cheo cua)) tinh - hanh ((tang va) OR (trang va)) dung cong tac toan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chua) or (cheo cua)) tinh - hanh ((tang va) OR (trang va)) dung cong tac toan cau*".