Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va thanh » gia thanh, va tinh, le thanh
tinh cua » trinh cua, sinh cua, tinh chat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cai nam » hai nam, mai nam, chi nam
cua tre » cua te, cuu tre, cua triet
ca nam » cua nam, ha nam, va nam
x hoi » xa hoi, o hoi, x ho

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. hieu ((ca nam) OR (cai nam)) qua ((va thanh) or (ban thanh)) tinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ((ca nam) OR (cai nam)) qua ((va thanh) OR (ban thanh)) tinh cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu ((ca nam) OR (cai nam)) qua ((va thanh) or (ban thanh)) tinh cua tre*".