Perhaps you should try some spelling variations:
toan khoan » toan khoa, toan phan, toan hoat
khoan danh » khoan dinh, khoan thanh, khoa dang
thanh phan » thanh pho, thanh san, thanh toan
ban thanh » ban hanh, ban hang
mach hoc » cach hoc, dich hoc, anh hoc
cuu toan » cuu hoan, cua toan, huu toan
danh hoa » thanh hoa, khanh hoa, nganh hoa
choi ban » choi dan, cho ban, chi ban
tu mach » tu cach, tu manh, tu hach
hoc bai » hoc giai
hoc dai » hoc dan

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 toan khoan danh hoa ((hoc bai) or (hoc dai)) choi ban thanh phan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien cuu toan khoan danh hoa ((hoc bai) OR (hoc dai)) choi ban thanh phan.
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cuu toan khoan danh hoa ((hoc bai) or (hoc dai)) choi ban thanh phan*.