Perhaps you should try some spelling variations:
sach dong » sach dung, sach song, sach rong
danh khoa » doanh khoa, anh khoa, danh hoa
dong tac » cong tac, dong tai, dong bac
dong hoc » dong co, dong luc
khoa hoc » hoa hoc
hoi luan » hoa luan, hoc luan, khoa luan
te sach » toc sach
mon hoc » toan hoc
van van » van ban, tan van, san van
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 dong tac, nghien cuu ((mon hoc) or (dong hoc)) danh khoa hoc ma hoi luan van van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach dong tac, nghien cuu ((mon hoc) OR (dong hoc)) danh khoa hoc ma hoi luan van van.
• Adding a wildcard symbol may retrieve word variants: te sach dong tac, nghien cuu ((mon hoc) or (dong hoc)) danh khoa hoc ma hoi luan van van*.