Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
hoc danh » hoc anh, hoc hanh, hoc nganh
khoa hoc » hoa hoc
mai khoa » tai khoa, may khoa, dai khoa
te sach » toc sach
doi tac » dong tac
cuu mon » cuu mo, cuu mot, cuu cong
hoc mai » hoc ma, hoc dai, hoc bai
luan » quan, lan

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) OR (hoc dan)) khoa hoc mai khoa 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) OR (hoc dan)) khoa hoc mai khoa luan van ban".
• Adding a wildcard symbol may retrieve word variants: te sach doi tac, nghien cuu mon ((hoc danh) OR (hoc dan)) khoa hoc mai khoa luan van ban*.