Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
duc van » duc va, duc tan, duc manh
xuc ban » duc ban, cuc ban, quoc ban
cuu ban » cuu van, cua ban, cuu san
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
anh vi » hanh vi, anh va, anh ve
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: tu sach ky nang x ho. hieu ve cac ((duc van) or (((xuc ban) or (cuu ban)))) anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x ho. hieu ve cac ((duc van) OR (((xuc ban) OR (cuu ban)))) anh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x ho. hieu ve cac ((duc van) or (((xuc ban) or (cuu ban)))) anh vi cua tre*.