Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
duc manh » suc manh, duc anh, duc minh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
va bao » va bai
x hoi » xa hoi, o hoi, 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 (x ho)). hieu va bao ((duc manh) or (duc va)) thanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (x ho)). hieu va bao ((duc manh) OR (duc va)) thanh van cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (x ho)). hieu va bao ((duc manh) or (duc va)) thanh van cua tre*.