Perhaps you should try some spelling variations:
"toc sach thanh tri" » "toc sach tranh tri", "toc sach tham tri", "toc danh thanh tri", "toc sach thanh tra", "toc sach thanh tai", "toc sach chinh tri", "hoc sach thanh tri", "doc sach thanh tri", "thuoc sach thanh tri"
"te sach nang tri" » "te cach mang tri", "te sach dung tri", "te sach danh tri", "te sach nang tai", "te sach lang tri", "te sach nang thi"
"te san quan tri" » "te van quan tri", "te ban quan tri", "te dan quan tri", "ke san quan tri", "tu san quan 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: (("te san quan tri") or ((("te sach nang tri") or ("toc sach thanh tri"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("te san quan tri") OR ((("te sach nang tri") OR ("toc sach thanh tri")))).
• Removing quotes may allow a broader search: (( te san quan tri ) or ((( te sach nang tri ) or ( toc sach thanh tri )))).
• Adding a wildcard symbol may retrieve word variants: (("te san quan tri") or ((("te sach nang tri") or ("toc sach thanh tri"))))*.