Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
quan quang » qua quang, quat quang, xuan quang
trong dang » truong dang, trong dan, trong dong
hoc thieu » toc thieu, hoc hien
quan quan » qua quan, quan luan, quang tuan
dang toan » dang tran, dan toan, dung toan
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: hoc thieu sang - tinh ((quan quang) or (quan quan)) dung trong dang toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - tinh ((quan quang) OR (quan quan)) dung trong dang toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - tinh ((quan quang) or (quan quan)) dung trong dang toan ban*.