Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach kem
va hanh » van hanh, va thanh, va danh
nam tuc » nam thuc, nam truc, nam tu
nang xa » lang xa, nang ma, mang xa
sach ty » sach y, sach tu, sach thu
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 (nang x)) hoi. hieu van nam tuc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) ((nang xa) OR (nang x)) hoi. hieu van nam tuc va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach ty)) ((nang xa) OR (nang x)) hoi. hieu van nam tuc va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) ((nang xa) OR (nang x)) hoi. hieu van nam tuc va hanh vi cua viet*.