Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
hoc khanh » hoc nhanh, hoc thanh, hoc hanh
phong hoc » phong ho, thong hoc, phuong hoa
cac dong » cac duong, cac cong, cac dang
dong hoc » dong co, dong luc
tinh van » trinh van, dinh van, tinh va
te sach » toc sach
so sach » so sanh, bo sach, co sach
va tinh » may tinh
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (so sach)) hoc tap, nghien cac dong hoc khanh phong hoc ma hoi va tinh van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (so sach)) hoc tap, nghien cac dong hoc khanh phong hoc ma hoi va tinh van.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (so sach)) hoc tap, nghien cac dong hoc khanh phong hoc ma hoi va tinh van*.