Perhaps you should try some spelling variations:
"hien phuong anh trinh luan van" » "hieu phuong anh trinh luan van", "dien phuong anh trinh luan van", "trien phuong anh trinh luan van", "hien phuong hoang trinh luan van", "hien phuong anh trinh luat van", "hien phuong anh trinh quan van", "hien phuong anh trinh han van", "hien phuong hanh trinh luan van", "hien phuong anh tinh luan van", "hien phuong thanh trinh luan van"
"hien phuong canh tranh luan van" » "hieu phuong canh tranh luan van", "dien phuong canh tranh luan van", "trien phuong canh tranh luan van", "hien phuong cach tranh luan van", "hien phong canh tranh luan van", "hien phuong danh tranh luan van", "hien phuong canh trinh luat van", "hien phuong canh doanh luan van", "hien phuong canh tang luan van"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("hien phuong anh trinh luan van") or ("hien phuong canh tranh luan van"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("hien phuong anh trinh luan van") OR ("hien phuong canh tranh luan van")).
• Removing quotes may allow a broader search: (( hien phuong anh trinh luan van ) or ( hien phuong canh tranh luan van )).
• Adding a wildcard symbol may retrieve word variants: (("hien phuong anh trinh luan van") or ("hien phuong canh tranh luan van"))*.