Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, tao duoc
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
sac ky » cac ky, sai ky
di su » doi su, ki su, da 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 ty) or (sac ky)) nang xa hoi. hieu va ((cao duc) OR (giao duc)) va hanh di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sac ky)) nang xa hoi. hieu va ((cao duc) OR (giao duc)) va hanh di su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sac ky)) nang xa hoi. hieu va ((cao duc) OR (giao duc)) va hanh di su triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sac ky)) nang xa hoi. hieu va ((cao duc) OR (giao duc)) va hanh di su triet*.