Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
trinh han » trinh quan
doi hieu » doi chieu, doc hieu, doi hien
ban cong » bang cong, van cong, phan cong
cong dan » cong san, cong tan, huong dan
toan cao » toan ban
toan tap » toan ban

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)) ban cong dan ((toan cao) OR (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh ((tinh quang) OR (trinh han)) ban cong dan ((toan cao) OR (toan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - hanh ((tinh quang) or (trinh han)) ban cong dan ((toan cao) OR (toan tap))".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh ((tinh quang) or (trinh han)) ban cong dan ((toan cao) OR (toan tap))*.