Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
lang van » dang van, tang van, hoang van
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
va cham » va chat, va tham
ve cham » ve chat, vu cham, ve chim
lang xa » lang ha, dang xay
san ky » sang ky, van ky, dan ky
vi cua » vai cua, di cua
tu san » thu san, tu ban, tu can

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

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