Perhaps you should try some spelling variations:
hien nhanh » thien thanh, tien thanh, dien thanh
hanh trang » thanh trung, canh tranh, hanh trinh
thong cong » trong cong, thong thong, phong chong
hien hanh » dieu hanh
tong cong » trong cong, cong cong, dung cong
trang va » tran van, hang va
tan han » tan nhan, tran han, tan van
han tap » han tai, toan tap, nhan tai

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 nhanh) OR (hien hanh)) - hanh trang va ((thong cong) or (tong cong)) tan han tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien nhanh) OR (hien hanh)) - hanh trang va ((thong cong) OR (tong cong)) tan han tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien nhanh) OR (hien hanh)) - hanh trang va ((thong cong) or (tong cong)) tan han tap".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien nhanh) OR (hien hanh)) - hanh trang va ((thong cong) or (tong cong)) tan han tap*.