Perhaps you should try some spelling variations:
tham nghiem » trac nghiem, thuc nghiem, thi nghiem
thu nghiem » thuc nghiem, thi nghiem
duong manh » duong van
manh tham » manh thang, sach tham, manh toan
nghiem de » nghiem d, nghiem do, nghiem te
sach thu » sach thue, sach thieu, sach tham
bo sach » co sach, hoc sach
de hoc » te hoc, du hoc, dien hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( bo sach thu nghiem _ hoc ) or ( duong manh tham nghiem de hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( bo sach thu nghiem _ hoc ) OR ( duong manh tham nghiem de hoc ))*.