Perhaps you should try some spelling variations:
chang nang » chang wang, thong nang, chai nang
hieu lang » chieu sang, hieu quang, nhieu tang
hieu manh » chieu xanh, hieu nganh, dieu hanh
bang cong » dang cong, bang song, hang cong
cao bang » cao dang, cao tang, cao nang
cong tap » cuong tap, cong tac, cong tan
toan cau » toan ban, toan tap, toan tai
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: hoc ((hieu lang) or (hieu manh)) - chang nang cao bang cong tap ((toan cau) OR (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (hieu manh)) - chang nang cao bang cong tap ((toan cau) OR (toan cao)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu lang) or (hieu manh)) - chang nang cao bang cong tap ((toan cau) OR (toan cao))".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) or (hieu manh)) - chang nang cao bang cong tap ((toan cau) OR (toan cao))*.