Perhaps you should try some spelling variations:
thanh lap » thanh san, phan lap, thanh hai
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
hanh lai » hanh lam, hanh tai, thanh loi
van cham » van chat, van tham, va cham
cham duc » pham duc, cham soc, pham duy
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 ky nang ((x hoi) or (o hoi)). hieu van cham duc van ((hanh lai) OR (thanh lap)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (o hoi)). hieu van cham duc van ((hanh lai) OR (thanh lap)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (o hoi)). hieu van cham duc van ((hanh lai) OR (thanh lap)) cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (o hoi)). hieu van cham duc van ((hanh lai) OR (thanh lap)) cua viet*.