Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
doanh khoa » toan khoa
von doanh » van doanh, voi doanh, toan doanh
khoa hoc » hoa hoc
phan van » pham van, thanh van, luan van
tu sach » thu sach, su sach, te sach
hoc tai » hoc dai, hoc bai, hoc giai
huu mot » cuu mot, huy mot, hieu mot
mot von » mot con, mot cong, mot dong
hoc mai » hoc ma, hoc dai, hoc bai
mai hoi » mai khoi, dai hoi, lai hoi
va phan » van phan, va phat, va phap

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 ((hoc tai) or (hoc tap)), nghien huu mot von doanh khoa hoc mai hoi va phan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((hoc tai) OR (hoc tap)), nghien huu mot von doanh khoa hoc mai hoi va phan van.
• Adding a wildcard symbol may retrieve word variants: tu sach ((hoc tai) or (hoc tap)), nghien huu mot von doanh khoa hoc mai hoi va phan van*.