Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh quan » tinh quang, trinh luat, trinh han
duong cong » luong cong, duong trong, trong cong
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
phan cau » phan dau, phan cac, phan lap
ho hieu » ho chieu, hoi hieu, nho hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu lang - hanh trinh quan ((duong cong) or (dung cong)) dan ((phan cau) OR (phan tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - hanh trinh quan ((duong cong) OR (dung cong)) dan ((phan cau) OR (phan tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - hanh trinh quan ((duong cong) or (dung cong)) dan ((phan cau) OR (phan tu))".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - hanh trinh quan ((duong cong) or (dung cong)) dan ((phan cau) OR (phan tu))*.