Perhaps you should try some spelling variations:
sach hoc » cach hoc, sach hoi, mach hoc
dan hoat » van hoa, dan hoc, danh hoa
hoat hoc » hoa hoc, hoat ho, khoa hoc
cau phan » chau phan, cuu phan, cac phan
phan van » pham van, thanh van, luan van
su sach » so sach, vu sach
mon hoc » toan hoc, dong hoc
hoi cau » hoi chu, hoc cau, hoa cau
hoc xa » hoc ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach hoc tap, nghien cuu ((mon hoc) or (co hoc)) dan hoat hoc xa hoi cau phan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoc tap, nghien cuu ((mon hoc) OR (co hoc)) dan hoat hoc xa hoi cau phan van.
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cuu ((mon hoc) or (co hoc)) dan hoat hoc xa hoi cau phan van*.