Perhaps you should try some spelling variations:
"cong trinh luan van thi cong ham luong" » "cong trinh luat van thi cong ham luong", "cong trinh quan van thi cong ham luong", "cong trinh han van thi cong ham luong", "cong trinh luan van thi cong hai luong", "cong trinh luan van thi cong chat luong", "cong trinh luan van thi cong hang luong", "cong trinh luan van tai cong ham luong", "cong trinh luan van thi cong pham luong", "cong trinh luan van thi cong ha luong", "cong trinh luan dan thi cong ham luong", "cong trinh luan van thu cong ham luong"
"cong trinh luan van thien cong ham luong" » "cong trinh luat van thien cong ham luong", "cong trinh quan van thien cong ham luong", "cong trinh han van thien cong ham luong", "cong trinh luan van thien cong hai luong", "cong trinh luan van thien cong chat luong", "cong trinh luan van thien cong hang luong", "cong trinh luan van tien cong ham luong", "cong trinh luan van hien cong ham luong", "cong trinh luan van chien cong ham luong", "cong trinh luan van thien cong pham luong", "cong trinh luan van thien cong ha luong", "cong trinh luan van taien cong ham luong", "cong trinh luan dan thien cong ham luong", "cong trinh luan van thuen cong ham luong"

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: (("cong trinh luan van thi cong ham luong") OR ("cong trinh luan van thien cong ham luong"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"cong trinh luan van thi cong ham luong\") OR (\"cong trinh luan van thien cong ham luong\"))".
• Removing quotes may allow a broader search: (( cong trinh luan van thi cong ham luong ) OR ( cong trinh luan van thien cong ham luong )).
• Adding a wildcard symbol may retrieve word variants: (("cong trinh luan van thi cong ham luong") OR ("cong trinh luan van thien cong ham luong"))*.