Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
sach trinh » sach tranh, hanh trinh, sach kinh
nghien te » nghiem te, nghiep ke, nghiep tu
nuoc sach » nguoi sach, hoc sach, cuoc cach
nghiep y » nghiep ly, nghiep cay, nghiep xay
nghiep o » nghiep so, nghiep co, nghiep nho
te sach » toc sach

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 trinh nghien te hoc ) or ( nuoc sach thieu ((nghiep y) or (nghiep o)) hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach trinh nghien te hoc ) OR ( nuoc sach thieu ((nghiep y) OR (nghiep o)) hoc )).
• Adding a wildcard symbol may retrieve word variants: (( te sach trinh nghien te hoc ) or ( nuoc sach thieu ((nghiep y) or (nghiep o)) hoc ))*.