Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
mach hoc » cach hoc, dich hoc, anh hoc
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
hoc toan » hoc tan, hop toan, hoa toan
khoa hoc » hoa hoc
su mach » su sach
hoi van » hoi dan, hai van, hoi han
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 mach hoc tap, nghien cuu cong hoc toan khoa hoc xa ((hoi van) or (hoi va)) thanh toan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su mach hoc tap, nghien cuu cong hoc toan khoa hoc xa ((hoi van) OR (hoi va)) thanh toan.
• Adding a wildcard symbol may retrieve word variants: su mach hoc tap, nghien cuu cong hoc toan khoa hoc xa ((hoi van) or (hoi va)) thanh toan*.