Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach tru » sach truc, sach thu, sach tu
tru lang » tre lang, tru nang, tu lang
pham huu » pham duc, pham duy, phan huy
van hanh » van thanh, ban hanh, van anh
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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 tru lang xa hoi. hieu ve ((chao xu) or (pham huu)) van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tru lang xa hoi. hieu ve ((chao xu) OR (pham huu)) van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach tru lang xa hoi. hieu ve ((chao xu) or (pham huu)) van hanh vi cua tre*.