Perhaps you should try some spelling variations:
thanh than » thanh thanh, thanh thang, thanh toan
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
va thanh » gia thanh, ban thanh, va tinh
than cua » nhan cua, thai cua, ban cua
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
thuc va » thuc vat, thuc dan, thuc day
x hoi » xa hoi, o hoi, x ho
o hoc » co hoc, mo hoc, so 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 ty nang ((x hoi) or (o hoc)). hieu van nam thuc va thanh than cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (o hoc)). hieu van nam thuc va thanh than cua viet*.