Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, van thanh
ban thanh » ban hanh, ban hang
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
van cam » van nam, van cau, van dam
van lam » van nam
hoi cua » hoi chuc
y nang » ky nang, ly nang, v nang
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: so sach y nang xa hoi. hieu ((van cam) OR (van lam)) hoc ((dan thanh) or (ban thanh)) hoi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang xa hoi. hieu ((van cam) OR (van lam)) hoc ((dan thanh) OR (ban thanh)) hoi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang xa hoi. hieu ((van cam) OR (van lam)) hoc ((dan thanh) or (ban thanh)) hoi cua tu".
• Adding a wildcard symbol may retrieve word variants: so sach y nang xa hoi. hieu ((van cam) OR (van lam)) hoc ((dan thanh) or (ban thanh)) hoi cua tu*.