Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
van cau » van dau, van hau, van chat
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, 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 sach) or (te sach)) ((ky lang) or (ky tang)) 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 sach) OR (te sach)) ((ky lang) OR (ky tang)) xa hoi. hieu van cau luc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ((ky lang) or (ky tang)) xa hoi. hieu van cau luc va hanh vi cua tre*.