Perhaps you should try some spelling variations:
thanh thai » thanh hai, thanh tai, nhanh thai
minh thanh » dinh thanh, tinh thanh, hinh thanh
thai cua » than cua, tai cuc, tri cua
su sach » so sach, vu sach
cam duc » cao duc, pham duc, nam duoc
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi

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 tang ((ma hoi) OR (mai hoi)). hieu ve ((cam duc) or (cam xuc)) minh thanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang ((ma hoi) OR (mai hoi)). hieu ve ((cam duc) OR (cam xuc)) minh thanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky tang ((ma hoi) OR (mai hoi)). hieu ve ((cam duc) or (cam xuc)) minh thanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky tang ((ma hoi) OR (mai hoi)). hieu ve ((cam duc) or (cam xuc)) minh thanh thai cua tre*.