Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thieu sang » chieu sang, thieu quang, hieu lang
nhanh lang » nhanh quang, nhanh thang, nhan dang
nhung cong » dung cong, thong cong, hang cong
cong dan » cong san, cong tan, huong dan
toan cau » toan ban, toan tap, toan tai
toan cao » toan ban, toan tap
lang va » lang van, hang va, lang ha

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 khang)) - nhanh lang va nhung cong dan ((toan cau) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - nhanh lang va nhung cong dan ((toan cau) OR (toan cao)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) OR (thieu khang)) - nhanh lang va nhung cong dan ((toan cau) or (toan cao))".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) OR (thieu khang)) - nhanh lang va nhung cong dan ((toan cau) or (toan cao))*.