Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hanh di » hanh vi, hanh de, hang di
y nang » ky nang, ly nang, v nang
tuc va » thuc va, truc va, duc va
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 xa hoi. ((hieu van) OR (thien van)) luat ((tuc va) or (tuc xa)) hanh di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. ((hieu van) OR (thien van)) luat ((tuc va) OR (tuc xa)) hanh di cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. ((hieu van) OR (thien van)) luat ((tuc va) or (tuc xa)) hanh di cua tu".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. ((hieu van) OR (thien van)) luat ((tuc va) or (tuc xa)) hanh di cua tu*.