Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
dang cong » dung cong
tranh va » tranh van, trang va, trinh va
tran van » luan van
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 ((chieu sang) OR (chieu sach)) - canh ((tranh va) or (tran van)) dang cong tan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (chieu sach)) - canh ((tranh va) OR (tran van)) dang cong tan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (chieu sach)) - canh ((tranh va) or (tran van)) dang cong tan toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (chieu sach)) - canh ((tranh va) or (tran van)) dang cong tan toan cau*.