Perhaps you should try some spelling variations:
khong thuoc » khang thuoc, hong phuoc, dong thuoc
phan khong » phan hong, nhan khong, pham khong
nhan dann » nhan dang, phan dang, nhac dan
sach hoc » cach hoc, sach hoi, mach hoc
hoc phan » hoc dan, hoc pho
thuoc la » thuoc ma, thuoc va, thuoc tai
nhan dan » phan dau, gian dan, nhan tai
su sach » so sach, vu sach
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
la hoi » lai hoi, xa hoi, le hoi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoc tap, nghien cuu mon hoc phan khong thuoc la hoi va ((nhan dann) OR (nhan dan))~.
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cuu mon hoc phan khong thuoc la hoi va ((nhan dann) or (nhan dan))*.