Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
luat tuc » luat thue
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
y nang » ly nang, v nang, may nang
tuc va » thuc va, truc va, tuc xa
di cua » dai cua, doi cua, de cua
cua tu » cua tuc, cua su, cua cu

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