Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
chieu sach » chinh sach, chiet tach, chieu sang
toan tuan » toan quan, doan tuan, toan luan
tran tuan » tran xuan, tran quang, tran thanh
dung cong » dung trong
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cau » 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 ((thieu sang) or (chieu sach)) - thanh ((toan tuan) OR (tran tuan)) dung cong tan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (chieu sach)) - thanh ((toan tuan) OR (tran tuan)) dung cong tan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (chieu sach)) - thanh ((toan tuan) OR (tran tuan)) dung cong tan toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (chieu sach)) - thanh ((toan tuan) OR (tran tuan)) dung cong tan toan cau*.