Perhaps you should try some spelling variations:
"sinh de chinh tri mac-lenin giao trinh" » "sinh den chinh tri mac-lenin giao trinh", "sinh do chinh tri mac-lenin giao trinh", "sinh ve chinh tri mac-lenin giao trinh", "sinh dh chinh tri mac-lenin giao trinh", "sinh dai chinh tri mac-lenin giao trinh"
"sinh te chinh tri mac-lenin giao trinh" » "sinh tai chinh tri mac-lenin giao trinh", "kinh te chinh tri mac-lenin giao trinh", "sinh tu chinh tri mac-lenin giao trinh", "sinh tren chinh tri mac-lenin giao trinh"

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: (("sinh de chinh tri mac-lenin giao trinh") OR ("sinh te chinh tri mac-lenin giao trinh"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"sinh de chinh tri mac-lenin giao trinh\") OR (\"sinh te chinh tri mac-lenin giao trinh\"))".
• Removing quotes may allow a broader search: (( sinh de chinh tri mac-lenin giao trinh ) OR ( sinh te chinh tri mac-lenin giao trinh )).
• Adding a wildcard symbol may retrieve word variants: (("sinh de chinh tri mac-lenin giao trinh") OR ("sinh te chinh tri mac-lenin giao trinh"))*.