Perhaps you should try some spelling variations:
cuon sach » duong sach, cuoc cach, nuoc sach
van hanh » van thanh, ban hanh, van anh
co sach » bo sach, hoc sach
cam duc » cam xuc, cao duc, pham duc
cua tre » cua te, cua triet, dua tren
duc van » duc va, duc tan, duc manh
cuu tre » cau tren, cau treo
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
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: ((co sach) or (cuon sach)) y nang x hoi. hieu ve cam duc van hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (cuon sach)) y nang x hoi. hieu ve cam duc van hanh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: ((co sach) or (cuon sach)) y nang x hoi. hieu ve cam duc van hanh vi ((cua tre) or (cuu tre))*.