Perhaps you should try some spelling variations:
thanh nhan » thanh phan, thanh toan, doanh nhan
hang huong » hang thuong, hang luong, hoang phuong
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
doc hieu » toc thieu, hoc thieu, hoc hien
hieu luc » hieu luat, hieu qua
tinh cua » trinh cua, sinh cua, tinh chat
cua hang » cua dang, cua nhung, cua cong

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu luc - hanh tinh cua hang huong dan ((thanh nhan) OR (thanh san))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu luc - hanh tinh cua hang huong dan ((thanh nhan) OR (thanh san))".
• Adding a wildcard symbol may retrieve word variants: doc hieu luc - hanh tinh cua hang huong dan ((thanh nhan) OR (thanh san))*.