Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
hieu tinh » chieu tinh, lieu tinh, kieu tinh
luan dung » lan dung, luan dong, luan hung
dung cong » dung trong
van thang » van thanh, van khang, van hang
doc hieu » toc thieu, hoc thieu, hoc hien
van than » van thanh, van tuan, van phan

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 tinh - ((hanh trinh) or (canh tranh)) luan dung cong ((van than) OR (van thang)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu tinh - ((hanh trinh) OR (canh tranh)) luan dung cong ((van than) OR (van thang)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu tinh - ((hanh trinh) or (canh tranh)) luan dung cong ((van than) OR (van thang)) cau".
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - ((hanh trinh) or (canh tranh)) luan dung cong ((van than) OR (van thang)) cau*.