Perhaps you should try some spelling variations:
nguyen huu » nguyen duc
doanh nang » doanh sang, doanh nhung, doanh quang
hoa doanh » toan doanh, hoa dan
sach hoc » cach hoc, mach hoc, sach duoc
sach hoi » sach doi, sach moi, cach thoi
nang hoc » nang doc, nang luc, dong hoc
cau luan » cu luan, dau luan, lau luan
son hoa » so hoa, mon hoa, son ha
hoc cau » hoc cao, hoc cac, hoc can
ma hoc » va hoc, ma hoa, mo hoc

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) or (sach hoi)) tap, nguyen huu son hoa doanh nang hoc ma hoc cau luan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach hoc) OR (sach hoi)) tap, nguyen huu son hoa doanh nang hoc ma hoc cau luan van.
• Adding a wildcard symbol may retrieve word variants: tu ((sach hoc) or (sach hoi)) tap, nguyen huu son hoa doanh nang hoc ma hoc cau luan van*.