Perhaps you should try some spelling variations:
trinh quan » trinh luat
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
ban cong » bang cong, van cong, phan cong
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
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 - hanh ((tinh quang) or (((trinh han) OR (trinh quan)))) ban cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh ((tinh quang) OR (((trinh han) OR (trinh quan)))) ban cong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - hanh ((tinh quang) or (((trinh han) OR (trinh quan)))) ban cong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh ((tinh quang) or (((trinh han) OR (trinh quan)))) ban cong dan toan cao*.