Perhaps you should try some spelling variations:
"khoa luan tot nghien." » "khoa luan mot nghien." (Expand Search), "khoa luan tat nghien." (Expand Search), "khoa luan noi nghien." (Expand Search), "khoa quan tot nghien." (Expand Search), "khoa lang tot nghien." (Expand Search)
"hoa luan tot nghien." » "hoa luan mot nghien." (Expand Search), "hoa luan tat nghien." (Expand Search), "hoa luan noi nghien." (Expand Search), "hoa quan tot nghien." (Expand Search), "hoa lang tot nghien." (Expand Search)
"hoa luan tot nghiep." » "hoa quan tot nghiep." (Expand Search), "hoa lang tot nghiep." (Expand Search)

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: (("khoa luan tot nghien.") OR ((("hoa luan tot nghien.") OR ("hoa luan tot nghiep."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"khoa luan tot nghien.\") OR (((\"hoa luan tot nghien.\") OR (\"hoa luan tot nghiep.\"))))".
• Removing quotes may allow a broader search: (( khoa luan tot nghien. ) OR ((( hoa luan tot nghien. ) OR ( hoa luan tot nghiep. )))).
• Adding a wildcard symbol may retrieve word variants: (("khoa luan tot nghien.") OR ((("hoa luan tot nghien.") OR ("hoa luan tot nghiep."))))*.