Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu cach » tu cac
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
van cau » van dau, van hau, van chat
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc 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: ((tu cach) or (te sach)) ((ky lang) or (ky dang)) xa hoi. hieu van cau luc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (te sach)) ((ky lang) OR (ky dang)) xa hoi. hieu van cau luc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (te sach)) ((ky lang) or (ky dang)) xa hoi. hieu van cau luc va hanh vi cua tre*.