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