Perhaps you should try some spelling variations:
thue nghien » thuyet nghien, thuc nghiem, thu nghiem
thi nghiem » thuc nghiem
bach thue » bach hue, sach thue, bach thu
sach thi » sach thu, sach tai, sach thieu
nghiem d » nghiem de, nghiem do, nghiem _
su sach » so sach, vu sach
cuu hoi » cau hoi, cua hoi, cuu hoc
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: (( su sach thi nghiem d hoc ) OR ( vu bach thue nghien cuu hoi ))~.
• Adding a wildcard symbol may retrieve word variants: (( su sach thi nghiem d hoc ) or ( vu bach thue nghien cuu hoi ))*.