Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
thac toc » cac toc, thac cac, thi toc
van thac » van hac, van tham, van than
hieu van » hieu va, thien van, lieu va
lang van » dang van, tang van, hoang van
cua tre » cua te, cuu tre, cua triet
toc van » hoc van, toc san, tac van
mang xa » lang xa, mang may, dang xay
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
vi cua » vai cua, di cua
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky ((((nang xa) or (mang xa))) or (lang van)) hoi. hieu van thac toc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((((nang xa) OR (mang xa))) OR (lang van)) hoi. hieu van thac toc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((((nang xa) or (mang xa))) or (lang van)) hoi. hieu van thac toc van hanh vi cua tre*.