Perhaps you should try some spelling variations:
thi nghiem » thuc nghiem
trinh nghe » trinh nghien, trinh he, trinh nha
nghiem ad » nghiem d, nghiem ban, nghiem lam
anh trinh » hanh trinh, anh tinh, thanh trinh
nghe tin » nghe tinh, nghe tan, nghe pin
su sach » vu sach
so sach » so sanh, bo sach, co sach
tin hoc » sinh hoc
vu anh » vu khanh, vu thanh

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) OR (so sach)) thi nghiem ad hoc ) OR ( vu anh trinh nghe tin hoc ))~.
• Adding a wildcard symbol may retrieve word variants: (( ((su sach) or (so sach)) thi nghiem ad hoc ) or ( vu anh trinh nghe tin hoc ))*.