Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thi nghiem » thuc nghiem
nghien van » nghiem van, nguyen van, nghiep va
nghiep van » nghiep va, nghiem van, nghiep can
nghiem de » nghiem d, nghiem do, nghiem te
sach thi » sach thu, sach thieu, sach tham
sach tai » sach bai, sach tham, sach dao
su sach » so sach, vu sach
de hoc » te hoc, du hoc, dien hoc

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuat sach thi nghiem de hoc ) OR ( su sach tai ((nghien van) OR (nghiep van)) hoc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thuat sach thi nghiem de hoc ) or ( su sach tai ((nghien van) OR (nghiep van)) hoc ))~".
• Adding a wildcard symbol may retrieve word variants: (( thuat sach thi nghiem de hoc ) or ( su sach tai ((nghien van) OR (nghiep van)) hoc ))*.