Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
co sach » bo sach, cuon sach, hoc sach
ty nang » ty xang, ty hang, ly nang
hieu ve » hieu va, hieu van
cam tuc » cam xuc, cam tu, nam thuc
va hang » van hang, va nang, va lang
hang di » hang doi, hang vi, hang dien
tuc va » thuc va, truc va, tuc xa
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: co sach ((ty nang) OR (ky nang)) xa hoi. ((hieu ve) or (hieu qua)) cam tuc va hang di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ((ty nang) OR (ky nang)) xa hoi. ((hieu ve) OR (hieu qua)) cam tuc va hang di su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((ty nang) OR (ky nang)) xa hoi. ((hieu ve) or (hieu qua)) cam tuc va hang di su triet".
• Adding a wildcard symbol may retrieve word variants: co sach ((ty nang) OR (ky nang)) xa hoi. ((hieu ve) or (hieu qua)) cam tuc va hang di su triet*.