Perhaps you should try some spelling variations:
chieu quang » thieu quang, chu quang, hieu quan
hieu quang » thieu quang, hieu quan, hieu qua
trinh vat » trinh van, trinh luat, sinh vat
dang cong » dung cong
trinh va » trinh van, trinh ve, trinh vi
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: doi ((chieu quang) or (hieu quang)) - hanh ((trinh va) OR (trinh vat)) dang cong tan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu quang) OR (hieu quang)) - hanh ((trinh va) OR (trinh vat)) dang cong tan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu quang) or (hieu quang)) - hanh ((trinh va) OR (trinh vat)) dang cong tan toan cau".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu quang) or (hieu quang)) - hanh ((trinh va) OR (trinh vat)) dang cong tan toan cau*.