Perhaps you should try some spelling variations:
khien bang » phien ban, khien dong
truong cua » truong ca, truong quan, truong cao
hien sang » hien trang, chieu sang, thien bang
trung cua » trung tuan, trung cap, dung cua
dang nong » dang cong, hang nong, tang nong
nong dan » cong dan, nong san, nguong dan
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien sang) or (khien bang)) - thanh ((trung cua) OR (truong cua)) dang nong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sang) OR (khien bang)) - thanh ((trung cua) OR (truong cua)) dang nong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien sang) or (khien bang)) - thanh ((trung cua) OR (truong cua)) dang nong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sang) or (khien bang)) - thanh ((trung cua) OR (truong cua)) dang nong dan toan cao*.