Perhaps you should try some spelling variations:
trien quang » tran quang, tuyen quang, dien quang
thieu sang » chieu sang, thieu khang, thieu quang
nhung cong » dung cong, thong cong, hang cong
trang cua » tranh cua, trung cua, thang cua
tang cua » mang cua, hang cua, tang luan
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
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 ((thieu sang) or (trien quang)) - hanh ((trang cua) OR (tang cua)) nhung cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (trien quang)) - hanh ((trang cua) OR (tang cua)) nhung cong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (trien quang)) - hanh ((trang cua) OR (tang cua)) nhung cong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (trien quang)) - hanh ((trang cua) OR (tang cua)) nhung cong dan toan cao*.