Perhaps you should try some spelling variations:
mai viet » thi viet
cua viet » ca viet, hoa viet, cua vat
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
va nay » va ngay, va cay
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 tu)) nang xa hoi. hieu va nay xuc va hanh vi ((cua viet) or (mai viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach tu)) nang xa hoi. hieu va nay xuc va hanh vi ((cua viet) OR (mai viet)).
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach tu)) nang xa hoi. hieu va nay xuc va hanh vi ((cua viet) or (mai viet))*.