Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh tai, hanh van
chat tuc » chat xuc, luat tuc, chat huu
sach ky » sac ky, sach y, sach ty
hanh va » hang va, hanh vi
tu sach » thu sach, su sach, te sach
hieu ve » hieu va
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
tuc va » thuc va, truc va, tuc xa
ma hoi » mai hoi, xa hoi, ma hoa
thiet » thieu

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 tang ma hoi. ((hieu ve) or (hieu van)) chat tuc va ((hanh vai) OR (hanh va)) va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ma hoi. ((hieu ve) OR (hieu van)) chat tuc va ((hanh vai) OR (hanh va)) va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang ma hoi. ((hieu ve) or (hieu van)) chat tuc va ((hanh vai) OR (hanh va)) va thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang ma hoi. ((hieu ve) or (hieu van)) chat tuc va ((hanh vai) OR (hanh va)) va thiet*.