Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach kem
va hanh » van hanh, va thanh, va danh
hac tuc » thac toc, thai tuc
van hac » van hoc, van ha, van hai
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa
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: su ((sach ky) OR (sach ty)) ((nang xa) or (lang xa)) hoi. hieu van hac tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) ((nang xa) OR (lang xa)) hoi. hieu van hac tuc va hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach ty)) ((nang xa) or (lang xa)) hoi. hieu van hac tuc va hanh vi cua tre*".