Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
chat doc » chat hoc, chau doc, thuat doc
chat soc » cham soc, chat hoc, chat song
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
danh di » danh du, xanh di, danh dien
tu sach » thu sach, su sach, te sach
di cua » dai cua, doi cua, de cua
x hoi » o hoi, x ho, 5 hoi

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 ((x hoi) OR (xa hoi)). hieu van ((chat soc) or (chat doc)) va danh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). hieu van ((chat soc) OR (chat doc)) va danh di cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (xa hoi)). hieu van ((chat soc) or (chat doc)) va danh di cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (xa hoi)). hieu van ((chat soc) or (chat doc)) va danh di cua viet*.