Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
hanh hang » thanh hang, hang hang, hanh han
va thong » va thuong, va phuong, he thong
cong tan » cong tac, cong san, cong thanh
toan cau » toan cao, toan tap, toan tai
toan ban » van ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu lang) or (hieu nganh)) - hanh hang va thong cong tan ((toan cau) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (hieu nganh)) - hanh hang va thong cong tan ((toan cau) OR (toan ban)).
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) or (hieu nganh)) - hanh hang va thong cong tan ((toan cau) or (toan ban))*.