Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
cuu dong » cuu cong, cuu tong, cuu long
hoc danh » hoc anh, hoc hanh, hoc nganh
khoa hoc » hoa hoc
hoi luan » hoa luan, hoc luan, khoa luan
te sach » toc sach
doi tac » dong tac
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 doi tac, nghien cuu dong ((hoc danh) OR (hoc dan)) khoa hoc ma hoi luan van van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach doi tac, nghien cuu dong ((hoc danh) OR (hoc dan)) khoa hoc ma hoi luan van van".
• Adding a wildcard symbol may retrieve word variants: te sach doi tac, nghien cuu dong ((hoc danh) OR (hoc dan)) khoa hoc ma hoi luan van van*.