Perhaps you should try some spelling variations:
trung thanh » truong thanh
thieu sang » thieu khang, thieu quang, hieu lang
chieu sang » chieu sach, chieu xanh, hieu lang
bang cong » dang cong, bang song, hang cong
cong vang » cong lang, cong quang, cong ngang
vang van » dang van, tang van, lang van

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((thieu sang) OR (chieu sang)) - hanh ((trung tam) or (trung thanh)) bang cong vang van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((thieu sang) OR (chieu sang)) - hanh ((trung tam) OR (trung thanh)) bang cong vang van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((thieu sang) OR (chieu sang)) - hanh ((trung tam) or (trung thanh)) bang cong vang van ban".
• Adding a wildcard symbol may retrieve word variants: toc ((thieu sang) OR (chieu sang)) - hanh ((trung tam) or (trung thanh)) bang cong vang van ban*.