Perhaps you should try some spelling variations:
toan giao » ton giao, toan cao, hoa giao
toc sach » hoc sach, doc sach, thuoc sach
van giao » nang giao, dan gian, dan giai
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua
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: ((te sach) OR (toc sach)) ky nang x hoi. hieu ((van giao) or (toan giao)) duc van hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang x hoi. hieu ((van giao) OR (toan giao)) duc van hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang x hoi. hieu ((van giao) or (toan giao)) duc van hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang x hoi. hieu ((van giao) or (toan giao)) duc van hanh va cua tre*.