Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
nhan dann » nhan dang, phan dang, nhac dan
cach thoi » cac thoi, cach thuc, cach noi
nhan dan » phan dau, gian dan, nhan tai
can khoa » san khoa, con khoa, van khoa
khoa hoc » hoa hoc
toan hoc » toan khoa, van hoc, hoa hoc
cua toan » cuu toan, xuan toan, cua thanh
thoi dap » hoi dap, thoi dai, thi dap
hoc can » hoc dan, hoc cao, hoc cac
hoa dau » hoa dan, hoa dai, hoa dam
tu cach » tu cac
hoc xa » hoc ma
xa hoa » xa khoa, 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: tu cach thoi dap, nghien cua toan hoc can khoa hoc xa hoa dau ((nhan dann) or (nhan dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach thoi dap, nghien cua toan hoc can khoa hoc xa hoa dau ((nhan dann) OR (nhan dan)).
• Adding a wildcard symbol may retrieve word variants: tu cach thoi dap, nghien cua toan hoc can khoa hoc xa hoa dau ((nhan dann) or (nhan dan))*.