Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh lap » thanh san, phan lap, thanh hai
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham duc » pham duc, cham soc, pham duy
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
duc van » duc va, duc tan, duc manh
lap cua » lai cua, tap cua, lam cua
x hoi » xa hoi, x ho, 5 hoi
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: tu sach ty nang ((x hoi) or (o hoi)). hieu van cham duc van thanh lap cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (o hoi)). hieu van cham duc van thanh lap cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) or (o hoi)). hieu van cham duc van thanh lap cua viet*.