Perhaps you should try some spelling variations:
doanh khoa » toan khoa
hoc doanh » hoa doanh, hoc danh, hoc dan
danh nhan » doanh nhan, thanh nhan, benh nhan
sach hoi » sach doi, sach moi, cach thoi
khoa hoc » hoa hoc
tu sach » thu sach, su sach, te sach
hoi tai » hoc tai, hoi trac
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
va nhan » van nhan, ca nhan, va phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach hoi tai, nghien cuu mon hoc doanh khoa hoc ma hoa ((va nhan) or (danh nhan)) dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoi tai, nghien cuu mon hoc doanh khoa hoc ma hoa ((va nhan) OR (danh nhan)) dan.
• Adding a wildcard symbol may retrieve word variants: tu sach hoi tai, nghien cuu mon hoc doanh khoa hoc ma hoa ((va nhan) or (danh nhan)) dan*.