Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh vi » hanh vi, thanh va, thanh ve
su sach » so sach, vu sach
luu tre » luu tru, cuu tre
tuc van » thuc van, truc van, tuc va
cau tuc » cau truc, cau tu, cau luc
luy tre » luyen tre
va cau » van cau, va cac, va dau
y nang » ky nang, ly nang, v nang
co hoi » co hoc, co loi
o hoi » o hoc, o hai, o hoa

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) or (co hoi)). lieu va cau tuc van thanh vi ((luu tre) OR (luy tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((o hoi) OR (co hoi)). lieu va cau tuc van thanh vi ((luu tre) OR (luy tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((o hoi) or (co hoi)). lieu va cau tuc van thanh vi ((luu tre) OR (luy tre))".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((o hoi) or (co hoi)). lieu va cau tuc van thanh vi ((luu tre) OR (luy tre))*.