Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, thieu quang
hoc thieu » toc thieu, hoc hien
trung cua » truong cua, trung tuan, trung cap
nong dan » nong san, nguong dan, huong dan
cong dan » cong san, cong tan, huong dan
toan cao » toan ban
toan tap » toan 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 - thanh trung cua ban ((nong dan) OR (cong dan)) ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - thanh trung cua ban ((nong dan) OR (cong dan)) ((toan cao) OR (toan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - thanh trung cua ban ((nong dan) OR (cong dan)) ((toan cao) or (toan tap))".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - thanh trung cua ban ((nong dan) OR (cong dan)) ((toan cao) or (toan tap))*.