Perhaps you should try some spelling variations:
"su sach chinh tri" » "su hanh chinh tri", "su sach kinh tri", "su soc chinh tri", "so sach chinh tri", "vu sach chinh tri"
"tu canh tranh tri" » "tu canh thanh tri", "tu canh tran tri", "tu canh trang trai", "thu canh tranh tri", "tu chanh tranh tri", "tu hanh tranh tri", "tu banh tranh tri", "tu cach tranh tri", "thu canhh tranh tri"
"tu can trang tri" » "tu can tranh tri", "tu ban trang tri", "tu cai trang tri", "tu can tran thi", "tu can quang tri", "tu cac trang tri", "thu canh trang tri"

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: (("su sach chinh tri") or ((("tu canh tranh tri") or ("tu can trang tri"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("su sach chinh tri") OR ((("tu canh tranh tri") OR ("tu can trang tri")))).
• Removing quotes may allow a broader search: (( su sach chinh tri ) or ((( tu canh tranh tri ) or ( tu can trang tri )))).
• Adding a wildcard symbol may retrieve word variants: (("su sach chinh tri") or ((("tu canh tranh tri") or ("tu can trang tri"))))*.