Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
toc sach » hoc sach, doc sach, thuoc sach
sach hoi » sach doi, sach moi, cach thoi
cong dac » cong tac, cong cac, cong da
cong dan » cong san, cong tan, huong dan
cong hoc » dong hoc, cong hoa, cong coc
nhan dan » phan dau, gian dan, nhan tai
hoi tap » hoi dap, hoc tap, hoi tai
va nhan » van nhan, ca nhan, va phan
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: toc sach hoi tap, nghien thu ((cong dac) OR (cong dan)) thanh cong hoc ma hoi va nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach hoi tap, nghien thu ((cong dac) OR (cong dan)) thanh cong hoc ma hoi va nhan dan".
• Adding a wildcard symbol may retrieve word variants: toc sach hoi tap, nghien thu ((cong dac) OR (cong dan)) thanh cong hoc ma hoi va nhan dan*.