Perhaps you should try some spelling variations:
dan doanh » van doanh, san doanh, ban doanh
doanh cua » doanh luan
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
cac tren » ca tren, cau tren, rac tren
tu sach » thu sach, te sach, tu cach
su sach » vu sach
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang

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) or (((su sach) or (so sach)))) y nang xa hoi. hieu van nam thuc dan doanh cua cac tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (((su sach) OR (so sach)))) y nang xa hoi. hieu van nam thuc dan doanh cua cac tren.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((su sach) or (so sach)))) y nang xa hoi. hieu van nam thuc dan doanh cua cac tren*.