Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
hoa nhanh » hoc nhanh, hoa khanh, hoa nhan
hoa thanh » hoan thanh, ha thanh, hoc thanh
chong hoc » chung hoc, chong doc, thong hoc
giang dan » gian dan, giang day, giang van
sach hoc » cach hoc, sach hoi, mach hoc
cac cong » cua cong
ha giang » bai giang, bac giang, ha tang
su sach » so sach, vu sach
hoc xa » hoc ma
hoi ha » hoi va, hoi khoa, hoi nhap

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 cac cong ((hoa nhanh) or (hoa thanh)) chong hoc xa hoi ha giang dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoc tap, nghien cac cong ((hoa nhanh) OR (hoa thanh)) chong hoc xa hoi ha giang dan.
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cac cong ((hoa nhanh) or (hoa thanh)) chong hoc xa hoi ha giang dan*.