Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc anh
va thanh » gia thanh, ban thanh, va tinh
thanh do » thanh de, thanh pho, thanh hoa
va triet » va thiet, va trien, ve triet
hoc cac » hoc cao
nam tuc » nam thuc, nam truc, nam tu
va nam » van nam, ha nam, va nay
tuc va » thuc va, truc va, tuc xa
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai
do va » do van, so va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc sach) or (hoc cac)) ky nang ((x hoi) OR (o hoi)). lieu va nam tuc va thanh do va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc cac)) ky nang ((x hoi) OR (o hoi)). lieu va nam tuc va thanh do va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (hoc cac)) ky nang ((x hoi) OR (o hoi)). lieu va nam tuc va thanh do va triet".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (hoc cac)) ky nang ((x hoi) OR (o hoi)). lieu va nam tuc va thanh do va triet*.