Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van mai » van hai, van ai, ban mai
xuc va » tuc va, luc va, xac va
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: tu sach ky nang xa hoi. hieu van thanh ((xuc va) or (duc va)) van mai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van thanh ((xuc va) OR (duc va)) van mai va thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van thanh ((xuc va) or (duc va)) van mai va thiet*.