Perhaps you should try some spelling variations:
thoi nghiem » thi nghiem, khoi nghiep, thuc nghiem
thuoc sach » hoc sach, nuoc sach, thuat sach
nghiem su » nghiem xu, nghiem ngu, nghiem dau
thu sach » tu sach, thuat sach, thu hoach
cac thoi » cac toi, cac hop, cac tro
nghe te » nghe tu, nghe theu, nghiem te
su hoc » tu hoc, du hoc, so hoc

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

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