Perhaps you should try some spelling variations:
thieu quang » hieu quang, thien quan, trien quang
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, hieu lang
hanh trung » hanh trang, manh trung, danh trung
luan chung » luan chinh
chung cong » nhung cong, chong cong, phung cong
van khang » van khanh, van thanh, van quang
khang ban » hang ban, khang benh, khang chan
cong van » cong vang, cong san, song van

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 (thieu quang)) - ((hanh trung) OR (thanh trung)) luan chung cong van khang ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu quang)) - ((hanh trung) OR (thanh trung)) luan chung cong van khang ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (thieu quang)) - ((hanh trung) OR (thanh trung)) luan chung cong van khang ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (thieu quang)) - ((hanh trung) OR (thanh trung)) luan chung cong van khang ban*.