Perhaps you should try some spelling variations:
tham nghiep » thuat nghiep, lam nghiep, tam nghien
thi nghiem » thuc nghiem
sach tham » sach nha
nghiep vu » nghiep va
sach thi » sach thu, sach tai, sach thieu
nghiem d » nghiem de, nghiem do, nghiem _
su sach » so sach, vu sach
vu hoc » tu hoc, va hoc, du hoc
d hoc » du hoc, ad hoc, de hoc

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 thi nghiem d hoc ) or ( su sach tham nghiep vu hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach thi nghiem d hoc ) OR ( su sach tham nghiep vu hoc )).
• Adding a wildcard symbol may retrieve word variants: (( su sach thi nghiem d hoc ) or ( su sach tham nghiep vu hoc ))*.