Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hanh vai » hanh vi, hanh va, hanh tai
chat tuc » chat xuc, luat tuc, chat huu
va thieu » va thiet, va hieu, va tieu
hieu ve » hieu van
hieu va » lieu va, hieu qua
ky tang » ky nang, ky dang, kho tang
va hanh » van hanh, va thanh, va danh
y tang » 6 tang, 7 tang, 5 tang
tuc va » thuc va, truc va, tuc xa
vai va » mai va, dai va, hai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((y tang) OR (ky tang)) xa hoi. ((hieu ve) or (hieu va)) chat tuc va hanh vai va thieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((y tang) OR (ky tang)) xa hoi. ((hieu ve) OR (hieu va)) chat tuc va hanh vai va thieu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((y tang) OR (ky tang)) xa hoi. ((hieu ve) or (hieu va)) chat tuc va hanh vai va thieu".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((y tang) OR (ky tang)) xa hoi. ((hieu ve) or (hieu va)) chat tuc va hanh vai va thieu*.