Perhaps you should try some spelling variations:
tham nhung » thi nhung
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
cong tham » chong tham, cong thai, hong tham
van thang » van thanh, van khang, van hang
hieu van » hieu va, thien van, lieu va
cong van » cong vang, cong san, song van
thang ca » thang cua, hang ca, tang ca

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 van) or (hieu lang)) - thanh cong tham nhung cong van thang ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu van) OR (hieu lang)) - thanh cong tham nhung cong van thang ca.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu van) or (hieu lang)) - thanh cong tham nhung cong van thang ca*.