Perhaps you should try some spelling variations:
khien bang » phien ban, khien dong
hien sang » hien trang, chieu sang, thien bang
trung cua » truong cua, trung tuan, dung cua
trung cap » truong cao, trung tam
tong cong » trong cong, cong cong, dung cong
cong anh » cong danh, dong anh, hong anh
tuan cau » toan cau, quan cau, tuan cu

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 (trung cap)) tong cong anh tuan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sang) OR (khien bang)) - thanh ((trung cua) OR (trung cap)) tong cong anh tuan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien sang) OR (khien bang)) - thanh ((trung cua) or (trung cap)) tong cong anh tuan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sang) OR (khien bang)) - thanh ((trung cua) or (trung cap)) tong cong anh tuan cau*.