Perhaps you should try some spelling variations:
thieu quang » hieu quang, thien quan, trien quang
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
cong tinh » cong trinh, cong vinh, long tinh
toan ban » van ban
va cong » tai cong, cua cong
cong va » dong va, cong ha, cong tac

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 (thieu quang)) - va cong va nhung cong tinh toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (thieu quang)) - va cong va nhung cong tinh toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) or (thieu quang)) - va cong va nhung cong tinh toan ban*.