Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
dien quang » diep quang, trien quang, lien quan
nang hang » nang sang, hang hang, cang thang
tong cong » trong cong, cong cong, dung cong
cong luan » tong luan, cong tuan, dong luan
va tong » va thong, va tuong, va trong

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 (dien quang)) - nang hang va tong cong luan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (dien quang)) - nang hang va tong cong luan van ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (dien quang)) - nang hang va tong cong luan van ban*.