Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thi nghiem » thuc nghiem
nghien van » nghiep van, nguyen van, nghiep va
nghiem van » nghiem va, nghiem ban, nghiep van
sach thai » sach tham, sac thai, sach tai
sach thi » sach thu, sach tai, sach thieu
nghiem d » nghiem de, nghiem _, nghiem h
su sach » so sach, vu sach
d hoc » du hoc, ad hoc, de 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 d hoc ) OR ( su sach thai ((nghien van) OR (nghiem van)) hoc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thuat sach thi nghiem d hoc ) or ( su sach thai ((nghien van) OR (nghiem van)) hoc ))~".
• Adding a wildcard symbol may retrieve word variants: (( thuat sach thi nghiem d hoc ) or ( su sach thai ((nghien van) OR (nghiem van)) hoc ))*.