Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
van tai » von tai, van tuan
xuc va » tuc va, luc va, xac va
tai va » thai va, mai va, tri 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) OR (thu sach)) ky nang xa hoi. hieu van cham ((xuc va) or (duc va)) van tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu van cham ((xuc va) OR (duc va)) van tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang xa hoi. hieu van cham ((xuc va) or (duc va)) van tai va thiet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu van cham ((xuc va) or (duc va)) van tai va thiet*.