Perhaps you should try some spelling variations:
trong thanh » truong thanh, trung thanh, thong thanh
hanh trinh » hanh chinh
rong thanh » dong thanh, cong thanh, truong thanh
hieu xanh » chieu xanh, hieu manh, hieu nganh
quan dung » quang dung, quan duong, qua dung
doc hieu » toc thieu, hoc thieu, hoc hien
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: doc hieu xanh - ((hanh trinh) or (canh tranh)) quan dung ((trong thanh) or (rong thanh)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - ((hanh trinh) OR (canh tranh)) quan dung ((trong thanh) OR (rong thanh)) toan tap.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - ((hanh trinh) or (canh tranh)) quan dung ((trong thanh) or (rong thanh)) toan tap*.