Perhaps you should try some spelling variations:
hoc toan » hoc tan, hop toan, hoa toan
khoa hoc » hoa hoc
phat dau » phan dau, pham dau, phap dau
su cach » su sach, tu cach, su cac
noi dap » hoi dap, noi da, noi dat
doi dap » hoi dap, doi dau, do dap
mo hoc » mon hoc, co hoc
hoc xa » hoc ma

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su cach ((noi dap) or (doi dap)), nghien cuu mo hoc toan khoa hoc xa hoi va phat dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su cach ((noi dap) OR (doi dap)), nghien cuu mo hoc toan khoa hoc xa hoi va phat dau.
• Adding a wildcard symbol may retrieve word variants: su cach ((noi dap) or (doi dap)), nghien cuu mo hoc toan khoa hoc xa hoi va phat dau*.