Perhaps you should try some spelling variations:
lcanh tranh » lanh tranh, can tranh, lan tranh
thi nghiem » thuc nghiem
nghiem tin » nghiem tinh, nghiem tien, nghiem tieng
sach thi » sach thu, sach tai, sach thieu
nghiem d » nghiem de, nghiem do, nghiem _
su sach » so sach, vu sach
tin hoc » sinh 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 ((canh tranh) OR (lcanh tranh)) nghiem tin hoc ))~.
• Adding a wildcard symbol may retrieve word variants: (( su sach thi nghiem d hoc ) or ( vu ((canh tranh) or (lcanh tranh)) nghiem tin hoc ))*.