Perhaps you should try some spelling variations:
hieu nganh » hiem ngan, hieu manh, nghiep nganh
vien nganh » vien thanh
hanh trinh » canh tranh
luat nhung » luat chung, luat thuong, thuat nhung
nhung cong » dung cong, thong cong, hang cong
cong tinh » cong trinh, cong vinh, long tinh
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 nganh) OR (vien nganh)) - ((hanh trinh) or (hanh chinh)) luat nhung cong tinh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu nganh) OR (vien nganh)) - ((hanh trinh) OR (hanh chinh)) luat nhung cong tinh toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu nganh) OR (vien nganh)) - ((hanh trinh) or (hanh chinh)) luat nhung cong tinh toan cau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu nganh) OR (vien nganh)) - ((hanh trinh) or (hanh chinh)) luat nhung cong tinh toan cau*.