Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hanh vai » hanh vi, hanh va, hanh tai
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
cac vo » cac co, cac vi, cac bo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ky nang xa hoi. hieu ve cac vo van hanh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang xa hoi. hieu ve cac vo van hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang xa hoi. hieu ve cac vo van hanh vai cua tre*.