Perhaps you should try some spelling variations:
nghiem duoc » nghiem thuoc, nghe duoc
xa nghiem » xet nghiem, van nghiem, va nghien
sach thai » sach tham, sac thai, sach tai
duoc hoc » quoc hoi
so sach » so sanh, bo sach, co sach
sach xa » sach dao, sach nha, sach bai
su sach » vu sach
xu hoc » tu hoc, du hoc, xa hoc
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: (( so sach xa nghiem duoc hoc ) or ( su sach thai nghe ((((xu hoc) or (xa hoi))) or (su hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sach xa nghiem duoc hoc ) OR ( su sach thai nghe ((((xu hoc) OR (xa hoi))) OR (su hoc)) )).
• Adding a wildcard symbol may retrieve word variants: (( so sach xa nghiem duoc hoc ) or ( su sach thai nghe ((((xu hoc) or (xa hoi))) or (su hoc)) ))*.