Perhaps you should try some spelling variations:
thanh dong » thanh duong, thanh cong, hanh dong
dong thuoc » dung thuoc, dang thuoc, don thuoc
hoc thanh » hoc nhanh, hoan thanh, hoc phan
thuoc la » thuoc ma, thuoc va, thuoc tai
su sach » so sach, vu sach
hoi tap » hoi dap, hoi tai, hai tap
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
va pham » van pham, va phat, va phap
la hoi » lai hoi, xa hoi, le hoi

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