Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, ban thanh
thanh hoi » thanh hoai, thanh hoa, thanh hai
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
cua tuc » cua duc, cua thuoc, luat tuc
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
van am » van nam, van lam, van dam
am hoc » ad hoc
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: so sach ((y nang) OR (v nang)) xa hoi. hieu van am hoc dan thanh hoi ((cua tu) or (cua tuc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((y nang) OR (v nang)) xa hoi. hieu van am hoc dan thanh hoi ((cua tu) OR (cua tuc)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((y nang) OR (v nang)) xa hoi. hieu van am hoc dan thanh hoi ((cua tu) or (cua tuc))".
• Adding a wildcard symbol may retrieve word variants: so sach ((y nang) OR (v nang)) xa hoi. hieu van am hoc dan thanh hoi ((cua tu) or (cua tuc))*.