Perhaps you should try some spelling variations:
nang lai » nang tai, nang cai, nang hai
hanh vai » hanh vi, hanh va, hanh tai
mang lai » mang lam, mang luoi, dang loai
su sach » so sach, vu sach
cam duc » cam xuc, pham duc, nam duoc
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cao duc » dao duc, cao suc, giao duc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van

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

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