Perhaps you should try some spelling variations:
"toc sach phan me giai toan thong minh" » "toc sach phan me giai toan thong tin", "toc sach han me giai toan thong minh", "toc mach phan me giai toan thong minh", "toc sach phat me giai toan thong minh", "toc sach phan me giai doan thong minh", "toc sach phan me giai toa thong minh", "toc sach phan me gioi toan thong minh", "hoc sach phan me giai toan thong minh", "doc sach phan me giai toan thong minh", "thuoc sach phan me giai toan thong minh", "toc sach phan mem giai toan thong minh", "toc sach phan le giai toan thong minh", "toc sach phan mo giai toan thong minh", "toc sach phan de giai toan thong minh", "toc sach phan ve giai toan thong minh", "toc sach phan ke giai toan thong minh"
"vu bach ha ke nguoi con hoang minh" » "vu bach ha ke nguoi cong hoang minh", "vu bach ha ke nguoi co hoang minh", "vu bach ha ke nguoi cor hoang minh", "vu bach ha ke nguoi con hong minh", "vu bach ha ke nguoi hoan hoang minh", "vu bach ha le nguoi con hoang minh", "vu bach ha ky nguoi con hoang minh", "vu bach ha me nguoi con hoang minh", "vu bac ha ke nguoi con hoang minh", "vu bich ha ke nguoi con hoang minh", "vu sach ha ke nguoi con hoang minh", "vu bach hat ke nguoi con hoang minh", "vu bach kha ke nguoi con hoang minh"

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: (("toc sach phan me giai toan thong minh") or ("vu bach ha ke nguoi con hoang minh"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("toc sach phan me giai toan thong minh") OR ("vu bach ha ke nguoi con hoang minh")).
• Removing quotes may allow a broader search: (( toc sach phan me giai toan thong minh ) or ( vu bach ha ke nguoi con hoang minh )).
• Adding a wildcard symbol may retrieve word variants: (("toc sach phan me giai toan thong minh") or ("vu bach ha ke nguoi con hoang minh"))*.