Perhaps you should try some spelling variations:
"cac cong trinh nghien" » "cac cong kinh nghiem", "cac cong trinh dien", "cua cong trinh nghien"
"cau chuong trinh thiet" » "cau chuong trinh viet", "cau chuong trinh thi", "cac chuong trinh thiet", "cau phuong trinh thiet", "cac phuong trinh thiet"
"cao cong trinh nghe" » "cao cong trinh he", "cao cong trinh nha", "cao dang trinh nghe", "cua cong trinh nghe", "cao tang trinh nghe"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("cau chuong trinh thiet") or ("cac cong trinh nghien"))) or ("cao cong trinh nghe"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("cau chuong trinh thiet") OR ("cac cong trinh nghien"))) OR ("cao cong trinh nghe"))*.
• Removing quotes may allow a broader search: (((( cau chuong trinh thiet ) or ( cac cong trinh nghien ))) or ( cao cong trinh nghe ))*.