Perhaps you should try some spelling variations:
dinh dai » dinh dat, sinh dai, dinh dao
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu he » hieu ve, hiem he, hieu le
thu gia » thue gia, phu gia, thue giao
cuu tre » cua tre, cau tren, cau treo
ma hoi » mai hoi, ma hoa, me hoi
he nam » ha nam, nghe nam
cua te » cua tu

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 ((ma hoi) OR (xa hoi)). hieu he nam thu gia dinh dai ((cua te) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((ma hoi) OR (xa hoi)). hieu he nam thu gia dinh dai ((cua te) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((ma hoi) OR (xa hoi)). hieu he nam thu gia dinh dai ((cua te) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((ma hoi) OR (xa hoi)). hieu he nam thu gia dinh dai ((cua te) or (cuu tre))*.