Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van chat » cao chat
chat soc » cham soc, chat hoc, chat doc
cua viet » ca viet, cua vat, cua dieu
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh

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