Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
dung truong » duong truong, dung trong, dung trung
truong dang » trong dang, truong giang, truong quang
thieu sang » chieu sang, thieu quang, hieu lang
quang qua » quang cua, quang tuan, quang xuan
dang toan » dang tran, dan toan, dung toan
qua dung » quang dung, su dung, qua song
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: toc ((thieu sang) or (thieu khang)) - tinh quang qua dung truong dang toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((thieu sang) OR (thieu khang)) - tinh quang qua dung truong dang toan ban.
• Adding a wildcard symbol may retrieve word variants: toc ((thieu sang) or (thieu khang)) - tinh quang qua dung truong dang toan ban*.