Perhaps you should try some spelling variations:
nganh khong » nganh cong, nhanh chong, nganh nong
toc sach » hoc sach, doc sach, thuoc sach
sach dao » lanh dao
dau nhan » dac nhan, dam nhan, danh nhan
nhan dan » phan dau, gian dan, nhan tai
dao dap » dao dan, dao gap, do dap
hoa dau » hoa dan, hoa dai, hoa dam
mo hoc » mon hoc, co hoc
toan » tran

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach dao dap, nghien cuu mo hoc ((nganh khong) or (toan khoa)) hoc ma hoa dau nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach dao dap, nghien cuu mo hoc ((nganh khong) OR (toan khoa)) hoc ma hoa dau nhan dan.
• Adding a wildcard symbol may retrieve word variants: toc sach dao dap, nghien cuu mo hoc ((nganh khong) or (toan khoa)) hoc ma hoa dau nhan dan*.