Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
vai cuu » vai cua
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
cac co » cac cong
ma hoi » mai hoi, ma hoa, me hoi
cac lo » cac lop, cac bo, cac 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 ((ma hoi) or (xa hoi)). hieu ve ((cac lo) OR (cac co)) van hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((ma hoi) OR (xa hoi)). hieu ve ((cac lo) OR (cac co)) van hanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((ma hoi) or (xa hoi)). hieu ve ((cac lo) OR (cac co)) van hanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((ma hoi) or (xa hoi)). hieu ve ((cac lo) OR (cac co)) van hanh vai cuu tre*.