Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
dong x » dong xa, dong y, dong o
va cam » va cham, va cac, va cao
vi cua » vai cua, di 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: ((toc sach) or (hoc sach)) van dong x hoi. hieu va cam duc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) van dong x hoi. hieu va cam duc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) van dong x hoi. hieu va cam duc va hanh vi cua tre*.