Perhaps you should try some spelling variations:
sach tu » sach thu, cach tu, sach ty
nang xa » nang x, lang xa, nang ma
qua cao » qua cac, qua ca, qua cai
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
sac ky » cac ky, sai ky
doi su » oi su, don su, voi su
da su » dan su, dat su, va 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 tu) or (sac ky)) nang xa hoi. hieu qua cao duc va hanh ((da su) or (doi su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sac ky)) nang xa hoi. hieu qua cao duc va hanh ((da su) OR (doi su)) triet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sac ky)) nang xa hoi. hieu qua cao duc va hanh ((da su) or (doi su)) triet*.