Perhaps you should try some spelling variations:
"te sach trien thuc hanh khoa he thong" » "te sach tien thuc hanh khoa he thong", "te sach tren thuc hanh khoa he thong", "te sach thieu thuc hanh khoa he thong", "te sach trien thuoc hanh khoa he thong", "te sach trien thuat hanh khoa he thong", "te sach trien thuc anh khoa he thong", "te sach trien thuc hanh hoa he thong", "te sach trien thuc han khoa he thong", "toc sach trien thuc hanh khoa he thong", "te sach trien thuc hanh khoa hoc thong", "te sach trien thuc hanh khong he thong"
"su sach dao duc hang khoa phau thong" » "su sach dao duc hang khoa phap thong", "su sach dao duc hang khoa khau thong", "su sach dao duc hang khoa phan thong", "su sach dao duc dung khoa phau thong", "su sach dao duc hang hoa phan thong", "su sach dao duc hang khoa kham thong", "su sach dao duc hang khoa than thong", "su lanh dao duc hang khoa phau thong", "su sach dao duc thang khoa phau thong", "su sach dao duc hoang khoa phau thong", "su sach dao duc hung khoa phau thong", "so sach dao duc hang khoa phau thong", "vu sach dao duc hang khoa phau thong", "su sach giao duc hang khoa phau thong", "su sach tao duoc hang khoa phau 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 trien thuc hanh khoa he thong") or ("su sach dao duc hang khoa phau thong"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("te sach trien thuc hanh khoa he thong") OR ("su sach dao duc hang khoa phau thong")).
• Removing quotes may allow a broader search: (( te sach trien thuc hanh khoa he thong ) or ( su sach dao duc hang khoa phau thong )).
• Adding a wildcard symbol may retrieve word variants: (("te sach trien thuc hanh khoa he thong") or ("su sach dao duc hang khoa phau thong"))*.