Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, thong thong, phong chong
hien hanh » dieu hanh
trinh cua » tinh cua, trinh luat, trinh quan
tong cong » trong cong, cong cong, dung cong
tap toan » tap doan, tap quan, bai 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 ((hien hanh) or (hieu nganh)) - hanh trinh cua ((thong cong) OR (tong cong)) tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien hanh) OR (hieu nganh)) - hanh trinh cua ((thong cong) OR (tong cong)) tap toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien hanh) or (hieu nganh)) - hanh trinh cua ((thong cong) OR (tong cong)) tap toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien hanh) or (hieu nganh)) - hanh trinh cua ((thong cong) OR (tong cong)) tap toan cao*.