Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
hieu va » lieu va, hieu qua
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
cao duc » dao duc, cao suc, giao duc
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky danh » ky anh
ky dang » ky nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ky dang) or (ky danh)) mai hoi. ((hieu ve) or (hieu va)) cao duc va hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky dang) OR (ky danh)) mai hoi. ((hieu ve) OR (hieu va)) cao duc va hanh vai cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky dang) or (ky danh)) mai hoi. ((hieu ve) or (hieu va)) cao duc va hanh vai cuu tre*.