Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, nghiep nganh
duong hang » duong thang, duong hong, duong dang
hieu manh » chieu xanh, dieu hanh, hieu van
hien hanh » dieu hanh
manh hung » anh huong
cua duong » cua dong, cua huong, qua duong
hung cua » huong cua, chung cua, khung cua
hang bai » hang tai, hang ban, hang hai
bai toan » bai tap
toan cau » 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: doc ((((hieu manh) OR (hien hanh))) or (hieu nganh)) - manh hung cua duong hang bai toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((((hieu manh) OR (hien hanh))) OR (hieu nganh)) - manh hung cua duong hang bai toan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((((hieu manh) OR (hien hanh))) or (hieu nganh)) - manh hung cua duong hang bai toan cau*".