Perhaps you should try some spelling variations:
"te sach thieu hoc chuyen đe pho thong" » "te sach thieu khong chuyen đe pho thong", "te sach hieu hoc chuyen đe pho thong", "te sach tieu hoc chuyen đe pho thong", "te sach thieu so chuyen đe pho thong", "toc sach thieu hoc chuyen đe pho thong"
"te sach sinh hoc chuyen đe he thong" » "te sach sinh khong chuyen đe he thong", "te sach kinh hoc chuyen đe he thong", "te sach danh hoc chuyen đe he thong", "te sach song hoc chuyen đe he thong", "toc sach sinh hoc chuyen đe he thong"

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 sach thieu hoc chuyen đe pho thong") or ("te sach sinh hoc chuyen đe he thong"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("te sach thieu hoc chuyen đe pho thong") OR ("te sach sinh hoc chuyen đe he thong")).
• Removing quotes may allow a broader search: (( te sach thieu hoc chuyen đe pho thong ) or ( te sach sinh hoc chuyen đe he thong )).
• Adding a wildcard symbol may retrieve word variants: (("te sach thieu hoc chuyen đe pho thong") or ("te sach sinh hoc chuyen đe he thong"))*.