Perhaps you should try some spelling variations:
truong quan » trong quan, thong quan, luong quan
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quang » thieu quang, hieu quan, hieu qua
truong cua » truong ca, truong cao, huong cua
hang cong » dang cong, hang nong, bang cong
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cau » toan cao, toan ban, toan tap

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

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