Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hanh trang » thanh trung, canh tranh, hanh trinh
doc hieu » toc thieu, hoc thieu
trang va » tran van, hang va
va thong » va thuong, va phuong, he thong
cong san » cong tac
san dung » van dung, dan dung, tan dung

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) OR (hoc hien)) xanh - hanh trang va thong cong san dung tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) OR (hoc hien)) xanh - hanh trang va thong cong san dung tai".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) OR (hoc hien)) xanh - hanh trang va thong cong san dung tai*.