Perhaps you should try some spelling variations:
khong thuoc » khang thuoc, hong phuoc, dong thuoc
nghien huu » nghien cuu, nguyen huu, nhiem huu
nhan khong » nhan thong, nhanh chong, nganh khong
thuoc lai » thuoc tai, thuoc la, thuoc sai
mach hoc » cach hoc, dich hoc, bac hoc
huu toan » huu tuan, cuu toan, huy toan
toan hoc » toan khoa, van hoc, hoa hoc
hoc nhan » hoc nhanh, nhoc nhan, hoc phan
cau nhan » chau nhan, ca nhan, cu nhan
nhan dan » phan dau, gian dan, nhan tai
anh hoc » sinh hoc, benh hoc, hinh hoc
lai hoi » dai hoi, lai hoa, lai roi
hoi cau » hoi chu, hoc cau, hoa cau

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) or (anh hoc)) tap, nghien huu toan hoc nhan khong thuoc lai hoi cau nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((mach hoc) OR (anh hoc)) tap, nghien huu toan hoc nhan khong thuoc lai hoi cau nhan dan.
• Adding a wildcard symbol may retrieve word variants: tu ((mach hoc) or (anh hoc)) tap, nghien huu toan hoc nhan khong thuoc lai hoi cau nhan dan*.