Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
vien dai » hien dai
vien cac » vien bach, vien da, gian cac
vai cua » dai cua, hai cua, lai cua
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dap
va dau » va dao
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: thu sach ky nang x hoi. hieu ((vien cac) or (vien dai)) bo ((va dan) OR (va dau)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang x hoi. hieu ((vien cac) OR (vien dai)) bo ((va dan) OR (va dau)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang x hoi. hieu ((vien cac) or (vien dai)) bo ((va dan) OR (va dau)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang x hoi. hieu ((vien cac) or (vien dai)) bo ((va dan) OR (va dau)) vai cua tre*.