Perhaps you should try some spelling variations:
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
va cao » va cac, va co, va dao
di su » doi su, da su, de su
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (cac ky)) nang xa hoi. hieu va cao duc va hanh ((di su) or (ki su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (cac ky)) nang xa hoi. hieu va cao duc va hanh ((di su) OR (ki su)) triet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (cac ky)) nang xa hoi. hieu va cao duc va hanh ((di su) or (ki su)) triet*.