Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, van thanh
ban thanh » ban hanh, ban hang
cau thuc » cau truc, cuu thuc, can thuc
su sach » so sach, vu sach
y nang » ky nang, ly nang, v nang
va cau » van cau, va cac, va dau
nang o » nang co, nang ho, nang ro
ve luu » vi luu
ke luu » ke suu, ky luu, ke lu
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang o hoi. lieu va cau thuc ((dan thanh) OR (ban thanh)) ((ve luu) or (ke luu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang o hoi. lieu va cau thuc ((dan thanh) OR (ban thanh)) ((ve luu) OR (ke luu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang o hoi. lieu va cau thuc ((dan thanh) OR (ban thanh)) ((ve luu) or (ke luu)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang o hoi. lieu va cau thuc ((dan thanh) OR (ban thanh)) ((ve luu) or (ke luu)) tre*.