Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
te sach » toc sach
nang xa » nang x, lang xa, nang ma
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
cua tuc » cua duc, cua thuoc, luat tuc
y nang » ky nang, ly nang, v nang
cua tu » cua su, cua cu, cua te

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang xa hoi. ((hieu van) OR (lieu va)) cac nuoc va tinh va ((cua tu) or (cua tuc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang xa hoi. ((hieu van) OR (lieu va)) cac nuoc va tinh va ((cua tu) OR (cua tuc)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang xa hoi. ((hieu van) OR (lieu va)) cac nuoc va tinh va ((cua tu) or (cua tuc))".
• Adding a wildcard symbol may retrieve word variants: te sach y nang xa hoi. ((hieu van) OR (lieu va)) cac nuoc va tinh va ((cua tu) or (cua tuc))*.