Perhaps you should try some spelling variations:
truong quan » trong quan, luong quan, truong van
chieu sach » chinh sach, chiet tach, chieu sang
hieu quang » thieu quang, hieu quan, hieu qua
lang cong » dang cong, bang cong, hang cong
cong tinh » cong trinh, cong vinh, long tinh
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sach) or (hieu quang)) - thanh ((truong quan) OR (thong quan)) lang cong tinh toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu quang)) - thanh ((truong quan) OR (thong quan)) lang cong tinh toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sach) or (hieu quang)) - thanh ((truong quan) OR (thong quan)) lang cong tinh toan ban".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (hieu quang)) - thanh ((truong quan) OR (thong quan)) lang cong tinh toan ban*.