Perhaps you should try some spelling variations:
dang xay » dang van, van xay
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cam tuc » cam tu, nam thuc, dam thuc
va hanh » van hanh, va thanh, va danh
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang cao) OR (dang xay)) hoi. hieu ve ((cam tuc) OR (cam xuc)) va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang cao) or (dang xay)) hoi. hieu ve ((cam tuc) OR (cam xuc)) va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang cao) or (dang xay)) hoi. hieu ve ((cam tuc) OR (cam xuc)) va hanh vi cua tre*.