Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
cua duc » cua tuc, cua nuoc, cua quoc
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
ca duc » cao duc, ca dua, ha duc
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

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