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