Perhaps you should try some spelling variations:
"tu sach trien nghiep dan hoc" » "tu sach trinh nghien dan hoc", "tu sach vien nghien dan hoc", "tu sach bien nghien dan hoc", "tu sach tien nghiep dan hoc", "tu sach tren nghiep dan hoc", "tu sach thieu nghiep dan hoc", "tu sach trien nghiep can hoc", "tu sach trien nghiep dai hoc", "tu sach trien nghiep van hoc", "su sach trien nghiep dan hoc", "te sach trien nghiep dan hoc", "tu cach trien nghiep dan hoc", "tu sach trien nghiep dan toc"
"thu sach bai nghe dan hoc" » "thuat sach bai nghe dan hoc", "thuoc sach bai nghe dan hoc", "thu hoach bai nghe dan hoc", "thu sach dao nghe dan hoc", "thu cac bai nghe dan hoc", "thu sach xa nghe dan hoc", "thu sach thai nghe dan hoc", "thu sach van nghe dan hoc", "thu sach nam nghe dan hoc", "thu sach bai nghe van hoc", "thu sach bai nghe dan toc", "thu sach bai nghe dai hoc"

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: (("tu sach trien nghiep dan hoc") or ("thu sach bai nghe dan hoc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("tu sach trien nghiep dan hoc") OR ("thu sach bai nghe dan hoc")).
• Removing quotes may allow a broader search: (( tu sach trien nghiep dan hoc ) or ( thu sach bai nghe dan hoc )).
• Adding a wildcard symbol may retrieve word variants: (("tu sach trien nghiep dan hoc") or ("thu sach bai nghe dan hoc"))*.