Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, nghiep nganh
hieu manh » chieu xanh, dieu hanh, hien hanh
hanh tang » hanh trang, anh tang, hanh mang
tang luan » dung luan
luan dung » lan dung, luan dong, luan hung
hoang van » hang va
song van » trong van, duong van, dang van
toan tap » toan ban

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 (hieu nganh)) - hanh tang luan dung ((song van) or (hoang van)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu manh) OR (hieu nganh)) - hanh tang luan dung ((song van) OR (hoang van)) toan tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu manh) OR (hieu nganh)) - hanh tang luan dung ((song van) or (hoang van)) toan tap*".