Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
cach tu » cach thuc
va hanh » van hanh, va thanh, va danh
van cau » van dau, van hau, van chat
sach tu » sach thu, sach ty, sach uu
sac ky » cac ky, sai ky
cau tu » dau tu, cau truc
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sac ky) or (((sach tu) OR (cach tu)))) nang x hoi. hieu van cau tu va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sac ky) OR (((sach tu) OR (cach tu)))) nang x hoi. hieu van cau tu va hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sac ky) or (((sach tu) OR (cach tu)))) nang x hoi. hieu van cau tu va hanh vi cua tre*".