Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
hoc danh » hoc dan, hoc anh, hoc hanh
hoi luan » hoa luan, hoc luan, khoa luan
te sach » toc sach
doi tac » dong tac
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
mai hoi » mai khoi, dai hoi, lai hoi

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 mon hoc danh ((khoa hoc) OR (hoa hoc)) mai hoi luan van ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach doi tac, nghien cuu mon hoc danh ((khoa hoc) OR (hoa hoc)) mai hoi luan van ban".
• Adding a wildcard symbol may retrieve word variants: te sach doi tac, nghien cuu mon hoc danh ((khoa hoc) OR (hoa hoc)) mai hoi luan van ban*.