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 dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap
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 dan than 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 dan than cau.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - anh ((vang cua) or (dan cua)) tong cong dan than cau*.