Perhaps you should try some spelling variations:
thu nghiem » thuc nghiem, thi nghiem
nghiem ad » nghiem d, nghiem ban, nghiem lam
toc sach » hoc sach, doc sach, thuoc sach
sach thu » sach thue, sach thieu, sach tham
nghiem y » nghiep y, nghiem _, nghiem d
toc cac » hoc cac, tuc cac, ton cac
cac thu » cach thuc, cac thoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc sach thu nghiem y hoc ) or ( toc cac thu nghiem ad hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc sach thu nghiem y hoc ) OR ( toc cac thu nghiem ad hoc )).
• Adding a wildcard symbol may retrieve word variants: (( toc sach thu nghiem y hoc ) or ( toc cac thu nghiem ad hoc ))*.