Perhaps you should try some spelling variations:
"su sach bai thuc hanh khoa kham thong" » "su sach bai thuc hanh khoa khap thong", "su sach bai thuc hanh khoa khau thong", "su sach bai thuc hanh khoa pham thuong", "su sach bai thuc hang khoa kham thong", "su sach bai thuc anh khoa kham thong", "su sach bai thuc hanh hoa kham thong", "su sach bai thuc hanh kho khan thong", "su sach bai thuc hanh khoa than thong", "su sach dao thuc hanh khoa kham thong", "su cac bai thuc hanh khoa kham thong", "su sach xa thuc hanh khoa kham thong", "su sach bai thuoc hanh khoa kham thong", "su sach bao thuc hanh khoa kham thong", "su sach dai thuc hanh khoa kham thong", "so sach bai thuc hanh khoa kham thong", "vu sach bai thuc hanh khoa kham thong"
"thu sach tai thuc bach khoa phan cong" » "thu sach tai truc bach khoa phan cong", "thu sach tai thuc cach khoa phan cong", "thu sach tai thuoc sach khoa phan cong", "thu sach tai thuc anh khoa phan cong", "thu sach tai thuc bach hoa phan cong", "thu sach tai thuc bach khoa than cong", "thu sach tai thuc bach khoa phau cong", "thu sach tai thuc bach khoa thanh cong", "tu sach tai thuc bach khoa phan cong", "thuat sach tai thuc bach khoa phan cong", "thuoc sach tai thuc bach khoa phan cong", "thu sach tham thuc bach khoa phan cong", "thu sach dao thuc bach khoa phan cong", "thu sach xa thuc bach khoa phan cong", "thu sach thai thuc bach khoa phan cong", "thu sach tri thuc bach khoa phan cong", "thu sach dai thuc bach khoa phan cong"

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: (("su sach bai thuc hanh khoa kham thong") or ("thu sach tai thuc bach khoa phan cong"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("su sach bai thuc hanh khoa kham thong") OR ("thu sach tai thuc bach khoa phan cong")).
• Removing quotes may allow a broader search: (( su sach bai thuc hanh khoa kham thong ) or ( thu sach tai thuc bach khoa phan cong )).
• Adding a wildcard symbol may retrieve word variants: (("su sach bai thuc hanh khoa kham thong") or ("thu sach tai thuc bach khoa phan cong"))*.