Perhaps you should try some spelling variations:
"toc sach phat ngu - goc nhin su viet" » "toc sach tham ngu - goc nhin su viet", "toc cach pha ngu - goc nhin su viet", "toc sach dat ngu - goc nhin su viet", "hoc sach phat ngu - goc nhin su viet", "doc sach phat ngu - goc nhin su viet", "thuoc sach phat ngu - goc nhin su viet", "toc sach nhat ngu - goc nhin su viet", "toc sach phap ngu - goc nhin su viet", "toc sach pham ngu - goc nhin su viet", "toc sach phat ngu - goc nhan su viet", "toc sach phat ngu - goc nhin tu viet", "toc sach phat ngu - goc thien su viet"
"te sach nha ngu - goc nhin so viet" » "te sach nhat ngu - goc nhin so viet", "te sach nhan ngu - goc nhin so viet", "te sach nhanh ngu - goc nhin so viet", "te sach nha ngu - goc khien so viet", "te sach nha ngu - goc nhin moi viet", "te sach nha ngu - goc nhin hoc viet"

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 phat ngu - goc nhin su viet") or ("te sach nha ngu - goc nhin so viet"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("toc sach phat ngu - goc nhin su viet") OR ("te sach nha ngu - goc nhin so viet")).
• Removing quotes may allow a broader search: (( toc sach phat ngu - goc nhin su viet ) or ( te sach nha ngu - goc nhin so viet )).
• Adding a wildcard symbol may retrieve word variants: (("toc sach phat ngu - goc nhin su viet") or ("te sach nha ngu - goc nhin so viet"))*.