Perhaps you should try some spelling variations:
mach hoc » cach hoc, dich hoc, anh hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hop » tong hop, dong hoc, dong hoa
hop toan » hop hoan, phap toan, tap toan
khoa hoc » hoa hoc
van gian » van giang, dan gian, van giao
tu mach » tu cach, tu manh, tu hach
va gian » va gianh, va giai, va gia
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: tu mach hoc tap, nghien cuu dong hop toan khoa hoc xa hoi ((va gian) or (van gian)) dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien cuu dong hop toan khoa hoc xa hoi ((va gian) OR (van gian)) dan.
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cuu dong hop toan khoa hoc xa hoi ((va gian) or (van gian)) dan*.