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