Perhaps you should try some spelling variations:
dang xay » dang van, van xay
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
cuc ban » cua ban, cac ban, cuu ban
cau cuc » cau cua, cau luc, cau truc
van cau » van dau, van hau, van chat
sach ky » sach y, sach ty, sach kem
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
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: te ((sach ky) or (sac ky)) ((lang ha) or (dang xay)) hoi. hieu van cau cuc ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) ((lang ha) OR (dang xay)) hoi. hieu van cau cuc ban hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sac ky)) ((lang ha) or (dang xay)) hoi. hieu van cau cuc ban hanh vi cua tre*.