Perhaps you should try some spelling variations:
luan trong » quan trong, luat trong, luan tuong
hieu lang » chieu sang, hieu quang, nhieu tang
phan tang » phap tang, phan dang, phan cang
tang luan » dung luan
doi hieu » doi chieu, doc hieu, doi hien
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh 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 hieu lang - phan tang luan trong cong dan toan cau~.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - phan tang luan trong cong dan toan cau*.