Perhaps you should try some spelling variations:
chieu hanh » chieu xanh, dieu hanh, chi hanh
thong cong » trong cong, tong cong, thong thong
hien hanh » dieu hanh
tang cua » mang cua, tang luan, thong cua
hang cua » mang cua, hang ca, huong cua
cong tam » cong tac, cong tan, cong nam
tam toan » tap toan, tam than, pham 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: theo ((chieu hanh) OR (hien hanh)) - hanh ((tang cua) or (hang cua)) thong cong tam toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu hanh) OR (hien hanh)) - hanh ((tang cua) OR (hang cua)) thong cong tam toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu hanh) OR (hien hanh)) - hanh ((tang cua) or (hang cua)) thong cong tam toan cao".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu hanh) OR (hien hanh)) - hanh ((tang cua) or (hang cua)) thong cong tam toan cao*.