Perhaps you should try some spelling variations:
tong cong » trong cong, cong cong, dung cong
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
vang cua » mang cua, hang cua, tang cua
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cau » toan cao, toan ban, toan tap
dan cua » dan ca, ban cua, dai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - anh ((vang cua) or (dan cua)) tong cong tan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - anh ((vang cua) OR (dan cua)) tong cong tan toan cau.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - anh ((vang cua) or (dan cua)) tong cong tan toan cau*.