Perhaps you should try some spelling variations:
khao nghiep » khao nghiem, khoi nghiep, thuat nghiep
trach nhiem » trac nghiem
sach trach » sach tranh, sach truc, sat trach
sach khao » sach dao, sach nha, sach tham
nghiep du » nghiep dau, nghiep vu, nghiep tu
nhiem de » nghiem de, nhiem ve, nhiet de
te sach » toc sach
de hoc » te hoc, dien hoc
du hoc » tu hoc, duoc hoc

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 trach nhiem de hoc ) or ( te sach khao nghiep du hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach trach nhiem de hoc ) OR ( te sach khao nghiep du hoc )).
• Adding a wildcard symbol may retrieve word variants: (( te sach trach nhiem de hoc ) or ( te sach khao nghiep du hoc ))*.