Perhaps you should try some spelling variations:
cuon sach » duong sach, cuoc cach, co sach
dua tren » dung tren
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, cua thep
cuu tre » cau tren, cau treo
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: cuon sach ky nang x hoi. hieu va cam xuc va hanh vi ((((cua tre) OR (dua tren))) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: cuon sach ky nang x hoi. hieu va cam xuc va hanh vi ((((cua tre) OR (dua tren))) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "cuon sach ky nang x hoi. hieu va cam xuc va hanh vi ((((cua tre) OR (dua tren))) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: cuon sach ky nang x hoi. hieu va cam xuc va hanh vi ((((cua tre) OR (dua tren))) or (cuu tre))*.