Perhaps you should try some spelling variations:
sach ky » sac ky, sach ty, sach kem
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
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: su ((sach ky) OR (sach y)) ((nang xa) or (nang x)) hoi. hieu va cam xuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) ((nang xa) OR (nang x)) hoi. hieu va cam xuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach y)) ((nang xa) or (nang x)) hoi. hieu va cam xuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach y)) ((nang xa) or (nang x)) hoi. hieu va cam xuc va hanh vi cua tre*.