Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua dieu
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
nam xuc » cam xuc, nam xua, nam thuc
va hanh » van hanh, va thanh, va danh
va nam » van nam, ha nam, va nay
xuc va » duc va, tuc va, luc va

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 hoi. hieu va nam xuc va hanh vi ((cua viet) OR (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang xa hoi. hieu va nam xuc va hanh vi ((cua viet) OR (cua vat)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach ty)) nang xa hoi. hieu va nam xuc va hanh vi ((cua viet) OR (cua vat))".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) nang xa hoi. hieu va nam xuc va hanh vi ((cua viet) OR (cua vat))*.