Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cham luc » cham soc, nhan luc, cham cuu
cua viet » ca viet, hoa viet, cua dieu
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va
dau cua » dai cua, day cua, cau cua
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va, loc va
va dau » va dao

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 y nang xa hoi. ((hieu ve) OR (hieu van)) cham luc va dau cua ((cua viet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. ((hieu ve) OR (hieu van)) cham luc va dau cua ((cua viet) OR (cua vat))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. ((hieu ve) OR (hieu van)) cham luc va dau cua ((cua viet) or (cua vat))*".