Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
chat luc » chat xuc, chat lua, nhan luc
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va
va hanh » van hanh, va thanh, va danh
kiem va » kien va, kiem tra, nhiem va
luc va » duc va, tuc va, loc va
kem va » kiem van
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang xa hoi. ((hieu ve) or (hieu van)) chat luc va hanh ((kem va) or (kiem va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. ((hieu ve) OR (hieu van)) chat luc va hanh ((kem va) OR (kiem va)) thiet.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. ((hieu ve) or (hieu van)) chat luc va hanh ((kem va) or (kiem va)) thiet*.