Perhaps you should try some spelling variations:
hoc khanh » hoc nhanh, hoc thanh, hoc hanh
khanh hoa » thanh hoa, hang hoa
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
su sach » so sach, vu sach
hoa dau » hoa dan, hoa dam, hoa cau
hoa dai » hoa dan, hoc dai
hoc xa » hoc ma
doan » doanh, dan, toan

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 dong hoc khanh hoa hoc xa ((hoa dau) or (hoa dai)) chan doan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoc tap, nghien cuu dong hoc khanh hoa hoc xa ((hoa dau) OR (hoa dai)) chan doan.
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cuu dong hoc khanh hoa hoc xa ((hoa dau) or (hoa dai)) chan doan*.