Perhaps you should try some spelling variations:
thang cong » thanh cong, thang long, thong cong
thang lang » thang long, thuong lang, nhanh lang
hieu lang » chieu sang, hieu quang, nhieu tang
van thang » van thanh, van khang, van hang
hieu van » hieu va, thien van, lieu va
lang van » dang van, tang van, hoang van
cong dan » cong san, cong tan, huong dan
dan van » dang van, doan van, dao van

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 van)) - thang lang van thang cong dan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (hieu van)) - thang lang van thang cong dan van ban*.