Perhaps you should try some spelling variations:
sach ky » sach y, sach ty, sach kem
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ve cam » ve cham, ve cac, va cam
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) OR (sac ky)) nang ((xa hoi) or (o hoi)). hieu ve cam tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) nang ((xa hoi) OR (o hoi)). hieu ve cam tuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sac ky)) nang ((xa hoi) or (o hoi)). hieu ve cam tuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sac ky)) nang ((xa hoi) or (o hoi)). hieu ve cam tuc va hanh vi cua tre*.